Opinion for the court filed by Circuit Judge RADER. Dissenting opinion filed by Senior Circuit Judge ARCHER.
RADER, Circuit Judge.The Gillette Company (Gillette) owns U.S. Patent No. 6,212,777 (issued April 10, 2001) (the ’777 patent) for wet-shave safety razors with multiple blades. Gillette sued Energizer Holdings, Inc. (Energizer) in the United States District Court for the District of Massachusetts alleging Energizer’s QUATTRO®, a four-bladed wet-shave safety razor, infringes certain claims of the ’777 patent. The district court denied Gillette’s motion for a preliminary injunction because it found that the claims of the ’777 patent covered only a three-bladed razor, and, consequently, Gillette did not show a reasonable likelihood of success on its claim of literal infringement by Energizer’s four-bladed razor. The Gillette Co. v. Energizer Holdings, Inc., No. 03-11514-PBS, 2004 WL 3366162 (D.Mass. Jan. 15, 2004). Because the district court erred in construing the claims of the ’777 patent to cover only three-bladed safety razors, this court vacates and remands.
I.
The ’777 patent claims a disposable safety razor with a group of blades, each blade placed in a particular geometric position relative to the other blades of the -group. Prior art razors with multiple blades shaved closer to the skin than two-bladed razors but had “a serious detrimental in*1369fluence on other blade unit characteristics, most notably the drag forces experienced when the blade unit is moved over the skin, with the consequence that the overall performance of the blade unit [was] markedly inferior [compared to two-bladed razors] despite a closer shave being obtained.” ’777 patent, col. 1, II. 24-29.
The inventive contributions of the ’777 patent are varying progressively the exposure and spacing parameters of the blades to overcome the undesired drag forces produced by razors with multiple blades, not simply limiting the number of blades to three. “The blade exposure is defined to be the perpendicular distance or height of the blade edge measured with respect to a plane tangential to the skin contacting surfaces of the blade unit elements next in front of and next behind the edge.” Id. at col. 1, II. 50-59. Specifically, the blade closest to the guard (leading blade) is positioned with a negative exposure to (i.e. recessed below) its tangential plane. Id. The blade closest to the cap (trailing blade) is positioned with a positive exposure to (i.e., extending above) its tangential plane. Id. A blade in between the leading and trailing blades is positioned with an exposure with respect to its tangential plane in between the exposures of the leading and trailing blades with respect to their respective tangential planes. Id. at col. 2, II. 28-40. The result is a generally “progressive exposure” of the blades with each of the identified blades shaving closer to the skin than the preceding blade. This blade configuration reduces the drag forces produced by the blades and equalizes the work performed by each successive blade. Id. at col. 1, II. 63-66. Additionally, the span marks the distance between successive blades. A progressive span would involve gradually increasing the spaqing between the guard and the leading blade, each successive blade, and the trailing blade and the cap. See, e.g., id. at col. 2, II. 16-20. The progression of the blade span likewise reduces frictional drag, leading to a close and comfortable shave.
Claim 1 of the ’777 patent shows this progressive exposure innovation in shaving technology:
1. A safety razor blade unit comprising a guard, a cap, and a group of first, second, and third blades with parallel sharpened edges located between the guard and cap, the first blade defining a blade edge nearest the guard having a negative exposure not less- than -0.2 mm, and the third blade defining a blade edge nearest the cap having a positive exposure of not greater than +0.2 mm, said second blade defining a blade edge having an exposure not less than the exposure of the first blade and not greater than the exposure of the third blade.
777 patent, col. 4, II. 5-14.
The Energizer QUATTRO® razor is the accused infringing device. The QUAT-TRO® employs a cartridge with a guard, a cap, and four blades. The leading blade has a negative exposure of not less than - 0.2 mm; the trailing blade has a positive exposure of not greater than +0.2 mm. The QUATTRO® further has two middle blades with essentially the same exposure, which is greater than that of the leading blade and less than that of the trailing blade. In anticipation of Energizer’s launch of the QUATTRO®, Gillette filed a patent infringement suit asserting that the QUATTRO® infringed the claims of the ’777 patent. Shortly thereafter, Gillette moved for a preliminary injunction to enjoin Energizer from making and selling the QUATTRO®.
Following a two-day hearing, the district court denied Gillette’s motion, finding that Gillette had not shown a reasonable likelihood of success on its claim of literal infringement. Gillette, 2004 WL 3366162, at *1370*1. The trial court primarily based its decision on the conclusion that the terms “first,” “second,” and “third” of claim 1 limited the scope of that claim to a razor having solely three blades. Id., slip op. at 11. Gillette now appeals, and this court has jurisdiction under 28 U.S.C. § 1292(c)(1).
II
The grant of a preliminary injunction under 35 U.S.C. § 283 is within the discretion of the district court. This court reviews a preliminary injunction decision for an abuse of discretion. Novo Nordisk of N. Am., Inc. v. Genentech, Inc., 77 F.3d 1364, 1367 (Fed.Cir.1996). “An abuse of discretion may be established by showing that the court made a clear error of judgment in weighing relevant factors or exercised its discretion based upon an error of law or clearly erroneous factual findings.” Id.
As the moving party, Gillette is entitled to a preliminary injunction if it shows: (1) a reasonable likelihood of success on the merits of its claims; (2) irreparable harm if an injunction is not granted; (3) a balance of hardships tipping in its favor; and (4) the injunction’s favorable impact on the public interest. Reebok Int’l Ltd. v. J. Baker, Inc., 32 F.3d 1552, 1555 (Fed.Cir.1994). In order , to demonstrate a likelihood of success on the merits, Gillette has to show that, in light of the presumptions and burdens that will inhere at trial on the merits, (1) Energizer likely infringes the ’777 patent, and (2) the claims of the ’777 patent will likely withstand Energizer’s challenges to validity. Amazon.com, Inc. v. Barnesandnoble.com, Inc., 239 F.3d 1343, 1350 (Fed.Cir.2001). While Energizer raised issues of validity in opposition to Gillette’s motion for a preliminary injunction, the district court held that Gillette did not demonstrate a reasonable likelihood of success on the threshold issue of literal infringement. Therefore, the trial court did not address the validity issues. Accordingly, the validity of the ’777 patent is not before this court on appeal.
To review Gillette’s likelihood of success on its literal infringement claim, this court, as the trial court before it, must first determine the meaning and the scope of the claims on this preliminary record. See Oakley, Inc. v. Sunglass Hut Int’l, 316 F.3d 1331, 1339 (Fed.Cir.2003) (“An assessment of the likelihood of infringement, like a determination of patent infringement at a later stage in litigation, requires a two-step analysis. First, the court determines the scope and meaning of the patent claims . asserted. Second[ ], the properly construed claims are compared to the allegedly infringing device.”) (internal quotations, alterations, and citations omitted). “In construing claims, the analytical focus must begin and remain centered on the language of the claims themselves, for it is that language that the patentee chose to use to particularly point out and distinctly claim the subject matter which the paten-tee regards as his invention.” Interactive Gift Express, Inc. v. Compuserve, Inc., 256 F.3d 1323, 1331 (Fed.Cir.2001) (quoting 35 U.S.C. § 112, ¶ 2); see also SRI Int’l v. Matsushita Elec. Corp., 775 F.2d 1107, 1121 n. 14 (Fed.Cir.1985) (ere banc) (“Specifications teach. Claims claim.”).
Claim construction requires this court to place the claim language in its proper technological and temporal context. The best tools for this enterprise are the various forms of intrinsic evidence and, when appropriate, extrinsic evidence. See Vitronics, Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed.Cir.1996). The intrinsic evidence, “i.e., the patent itself, including the claims, the specification and, if in evidence, the prosecution history ... is the most significant source of the legally operative meaning of disputed claim language.” Id. (internal citation .omitted); see also United States v. Adams, 383 U.S. 39, 49, *137186 S.Ct. 708, 15 L.Ed.2d 572 (1966) (“[I]t is fundamental that claims are to be construed in the light of the specifications and both are to be read with a view to ascertaining the invention.”); Astrazeneca v. Mutual Pharm. Co., Inc., 384 F.3d 1333, 1336-37 (Fed.Cir.2004) (“[E]vidence intrinsic to the patent — particularly the patent’s specification, including the inventors’ statutorily-required written description of the invention — is the primary source for determining claim meaning.” (citing Bell Atl. Network Servs., Inc. v. Covad Communications Group, Inc., 262 F.3d 1258, 1268 (Fed.Cir.2001); Vitronics, 90 F.3d at 1582)).
Applying this case law, this court must determine, on this preliminary record, whether the language “comprising ... a group of first, second, and third blades” in the ’777 patent can encompass four-bladed safety razors (such as the QUATTRO®) or is limited to solely three-bladed safety razors. As explained below, this court discerns that claim 1 uses the “open” claim terms “comprising” and “group of,” in addition to other language, to encompass subject matter beyond a razor with only three blades. Moreover, the specification’s focus on blade exposures and express reference to “blade units with a plurality of blades,” ’777 patent, col. 1, II. 3-6, shows as well that this invention covers razors with more than three blades.
The objective of the invention of the ’777 patent is to reduce drag forces in safety razors with more than two blades. See id. at col. 1, II. 24-37. The ’777 patent accomplishes this objective by progressively increasing the blade exposure and the blade span. Id. at col. 1, II. 37-59. Indeed, the specification specifically acknowledges that it is not the three blades themselves which solve the prior art problem of detrimental drag forces, but instead the arrangement of three blades in a particular spatial configuration, stating “the novel aspects of the present invention residing in the provision of three blades set in the blade unit set in particular dispositions with respect to each other and the guard and the cap.” Id. at col. 3, .II. 16-19 (emphasis added). The written description likewise discusses these parameters with respect to the relative positioning of each of the three blades at length at column 1, line 60 through column 2, line 40. These principles of progressive blade exposure and progressive blade span could apply equally to four or five blades. Such a geometric arrangement of three, four, or even more blades will achieve a closer shave and, at the same time, minimize excess drag. It may be that a four-bladed safety razor is a less preferred embodiment. A four-bladed razor costs more to build, requires more parts, and adds more frictional drag compared to the three-bladed version. Nevertheless, a patentee typically claims broadly enough to cover less preferred embodiments as well as more preferred embodiments, precisely to block competitors from marketing less than optimal versions of the claimed invention.
' Indeed, the language of claim 1 of the ’777 patent encompasses more than only three-bladed razors. At the outset, the open language of claim 1 embraces technology that may add features to devices otherwise within the claim definition. Moleculon Research Corp. v. CBS, Inc., 793 F.2d 1261, 1271 (Fed.Cir.1986). The claim uses two terms to show this open-ended meaning. The word “comprising” transitioning from the preamble to the body signals that the entire claim is presumptively open-ended. Crystal Semiconductor Corp. v. TriTech Microelectronics Int’l, Inc., 246 F.3d 1336, 1347 (Fed.Cir.2001); Innovad Inc. v. Microsoft Corp., 260 F.3d 1326, 1333 (Fed.Cir.2001). Because the patentee invoked this open-ended treatment in claim 1 of the ’777 patent, the scope of claim 1 encompasses all safety *1372razors satisfying the elements set forth in claim 1. The addition of elements not recited in the claim cannot defeat infringement. See Crystal Semiconductor, 246 F.3d at 1348 (“[T]he transition ‘comprising’ creates a presumption that the recited elements are. only a'part of the device, that the claim does not exclude additional, unrecited elements. KCJ Corp. v. Kinetic Concepts, Inc., 223 F.3d 1351, 1356 (Fed.Cir.2000).”).
The claim element identifying the blades likewise uses another presumptively “open” claim term — “group of.” 777 patent, col. 4,1. 6. At the outset, the language “group of’ does not place any limits or closed implications on the elements following this broad designation. Claim drafters often use the term “group of’ to signal a Markush group. A Markush group lists specified alternatives in a patent claim, typically in the form: a member selected from the group consisting of A, B, and C. See Manual of Patent Examining Procedure § 803.2 (2004). A Markush group by its nature is closed. If an applicant tries to claim a Markush group without the word “consisting,” the PTO will insist upon the addition of this word to ensure a closed meaning. Thus, in order to “close” a Mar-kush group, the PTO insists on the transition phrase “group consisting of.” See Abbott Labs. v. Baxter Pharm. Prods., Inc., 334 F.3d 1274, 1280 (Fed.Cir.2003). Without the word “consisting” the simple phrase “group of’ is presumptively open. If intending to limit the claimed invention to a three-bladed razor, the patent drafter would not have used the words “group of.” Rather, the drafter would have used the words “group consisting of,” or the simple formulation “and first, second, and third blades.” Because the drafter chose to use the open .term “group of,” additional members in the element “group of ... blades” will not defeat, infringement. In other words, a razor with two “second blades,” as in the QUATTRO®, will still fall within the literal language of the claim.
The element at issue requires:
a group of first, second, and third blades with parallel sharpened edges located between the guard and cap, the first blade defining a blade edge nearest the guard having a negative exposure not less than -0.2 mm, and the third blade defining a blade edge nearest the cap having a positive exposure of not greater than + 0.2 mm, said second blade defining a blade edge having an exposure not less than the exposure of the first blade and not greater than the exposure of the third blade.
777 patent, col. 4, II. 5-14 (emphases added). This element clearly defines a “group of blades” as a subset of the total number qf blades in the razor, and specifically identifies which blades of the razor are the “first, second, and third” blades of the subset. The first blade in the group is the blade “nearest the guard,” or leading blade. The third blade in the group is the blade “nearest the cap,” or trailing blade. The second blade is defined by its exposure, and must “hav[e] an exposure not less than the exposure of the first blade and not greater than the exposure of the third blade.” Given that the first and third blades must be the leading and trailing blades, respectively, and in light of the specification’s discussion of a progressive blade exposure, the second blade must also be located between the first and third blades. See id. col. 1, I. 60 — col. 2, I. 40 (discussing a progressive blade exposure from a first blade to a second and third blades). Thus, any blade in between the first and third blades and with an exposure greater than that of the first blade and less than that of the third blade is a “second” blade in the claimed subset of blades. The accused QUATTRO® device, in fact, has two “second blades” because both of *1373the middle blades in the accused device meet the definition of the “second blade” set forth in the claim. Any subset of three blades in a blade unit meeting these definitions is a “group of blades” as defined by the clear language of the claim. This claim is not ambiguous. In fact, the paten-tee underscored this open-ended claim meaning by using both the open-ended transition phrase “comprising” for all elements of claim 1 as discussed above, and the open-ended claim term “group of’ for each part of this element.
The language of the claims depending from claim 1 also support reading “comprising” and “group of’ as open terms. Claim 2, which depends from claim 1, adds the limitation that “the span between the first blade edge and the guard is substantially smaller than a span between the edges of the first and second blades and the span between the edges of the second and third blades.” Id. at col. 4, II. 17-20 (emphases added). The patent drafter’s use of “a span” between the first and second blades recognizes that more than one such span may exist. On the other hand, the drafter’s use of “the span” to identify the span between the guard-and first blade recognizes that only one such span is possible.1
The terms “first, second, and third” are terms to distinguish different elements of the claim, not terms supplying a numerical limit. Thus, the “first,” “second,” and “third” blades need not necessarily appear in that order or necessarily limit the blade unit to only three blades. Instead, these ordinal terms designate different blades within the “unit” according to their location and elevation. The claim itself makes this distinction. The claim defines both the “first” and “third” blades in terms of their location relative to the guard and cap, respectively, and further specifies their respective elevations. The second blade is defined solely by its elevation and location between the leading and trailing blades. None of the blades in the “group” are defined by their consecutive order relative to the other blades.
To make it abundantly clear that the reference to “first,” “second,” and “third” blades was not a serial or numerical limitation, the claim does not follow a consecutive order (ie., it does not discuss the second blade after the first). The claim is thus clearly not using the ordinals — first, second, third — to show a consecutive numerical limit but only to distinguish or identify the various members of the group. The case law of this court supports this reading of the claim language “first, second, and third.” See 3M Innovative Props. Co. v. Avery Dennison Corp., 350 F.3d 1365, 1371 (Fed.Cir.2003) (“use of the terms ‘first’ and ‘second’ is common patent-law convention to distinguish between repeated instances of an element” and should not necessarily be interpreted to impose a serial limitation on a claim).
The specification provides further support for interpreting claim 1 to encompass razors with more than three blades. The first sentence of the written description of the invention teaches that “the invention ... relates in particular to safety razors having blade units with a plurality of blades.” ’777 patent, col. 1, II. 3-5 (emphasis added). This reference defines the “invention” to encompass “a plurality of blades,” thus eschewing any numerical limit on the number of blades. The written description buttresses this statement of the invention through its use of the same *1374open-ended “group of’ language used in claim 1. Id. at col. 1, II. 87-40 (“Thus, in accordance with the present invention there is provided a safety razor blade unit comprising a guard, cap and a group of three blades ....”) (emphasis added). The specification makes numerous references to a preferred embodiment of the invention with three blades, see, e.g., id. at col. 2, II. 50-53 and col. 4, II. 2-3, but that narrower embodiment does not impose a limit on the broader claim language as elucidated by the reference to “the invention” as embracing a “plurality of blades.” See Comark Communications v. Harris Corp., 156 F.3d 1182, 1186 (Fed.Cir.1998) (refusing to import limitations from the specification to the claims); Sjolund v. Musland, 847 F.2d 1573, 1581 (Fed.Cir.1988) (same); Texas Instruments, Inc. v. U.S. Int’l Trade Comm’n, 805 F.2d 1558, 1563 (Fed.Cir.1986) (“This court has cautioned against limiting the claimed invention to preferred embodiments or specific examples in the specification.”).
The prosecution of patents related to the ’777 patent also supports reading claim 1 as an open claim. The defendant itself endorsed an open interpretation of “comprising” when it argued to the European Patent Office (EPO) that a virtually identical claim in Gillette’s European counterpart to the ’777 patent would not exclude an arrangement with four or more blades. This blatant admission by this same defendant before the EPO clearly supports this court’s holding that those skilled in the art would construe the claims of the ’777 patent to encompass razors with more than three blades.
The district court adopted Energizer’s argument that the numerous (approximately thirty) references to “three,” “third” and “tertiary” in the specification limit 'the scope of the claims. Gillette, 2004 WL 3366162, at *5. However, “words or expressions of manifest exclusion” or “explicit” disclaimers in the specification are necessary to disavow claim scope. Housey Pharms., Inc. v. Astrazeneca UK Ltd., 366 F.3d 1348, 1352 (Fed.Cir.2004); Liebel-Flarsheim v. Medrad, Inc., 358 F.3d 898, 906 (Fed.Cir.2004). Despite the numerous cites to three-bladed razors plucked from the written description, no statement in the patent surrenders or excludes a four-bladed razor. Neither the district court nor Energizer refers to the “manifest” or “explicit” exclusion test. This patent and its prosecution record fall far short of any kind of disclaimer or disavowal. Not only did the patentee claim the invention with two open-ended terms (“comprising” and “group of’), but the specification expressly teaches that the invention encompasses a “plurality of blades.” This court declines to import limitations to the claims from the specification absent a “manifest” or “explicit” exclusion. Id. The patentee did not disclaim razors with more than three blades at all, let alone “manifestly,” or “explicitly.” Rather the patentee opened its teachings of the invention in the specification with an express statement that the “invention” covers “blade units with a plurality of blades.” ’777 patent, col. 1, II. 3-6. The applicant did not “manifestly” or “explicitly” disclaim blade units with a plurality of blades by expressly defining the invention in those exact terms. More important, the language of the claim itself, with its open transition phrases and use of ordinals to distinguish but not limit claim elements, shows that the invention embraces “a plurality of blades.”
Ill
Based on the preliminary record before this court, the district court erred in limiting the claims of the ’777 patent to encompass safety razors with solely three blades. Accordingly, this court vacates the district court’s denial of a preliminary injunction on the grounds of Gillette’s failure to show a likelihood of success on the merits of its *1375claim. However, because the claim construction set forth in this opinion is preliminary and based upon an incomplete record, the district court will have every opportunity to review and revisit this claim construction during development of a full record. Indeed, this court recognizes the difficulty imposed on a trial court to construe claim terms based upon a preliminary “likelihood” record. See, e.g., CVI/Beta Ventures, Inc. v. Tura, LP, 112 F.3d 1146, 1160 n. 7 (Fed.Cir.1997) (reversing its own earlier “likelihood” claim construction of terms that were appealed after a complete record); Bayer AG. v. Biovail Corp., 279 F.3d 1340, 1349 (Fed.Cir.2002) (holding that it was premature for this court to engage in its own claim construction where the district court had not performed a comprehensive claim construction based on a complete record); Metaullics Sys. Co. v. Cooper, 100 F.3d 938 (Fed.Cir.1996) (declining to construe patent claims on appeal from a denial of a preliminary injunction).
In light of the foregoing analysis, the decision of the district court is vacated and remanded for further proceedings consistent with this opinion, including analysis of Energizer’s invalidity defenses raised in opposition to Gillette’s motion for a preliminary injunction.
COSTS
Each party shall bear its own costs.
VACATED and REMANDED
. Dependent claims 9 and 10 use “the span” and "the exposure/’ respectively, to refer to the span and exposure of the second blade. '777 patent, col. 4, II. 41-45. This definitive recitation of a single span and exposure likely limits these dependent claims to a single second blade, i.e., a three-bladed embodiment of the invention.