Appellant Dancy was convicted under a two count indictment charging him with dispensing and distributing a narcotic drug not in the original stamped package in violation of 26 U.S.C.A. § 4704 (1967) and with selling, bartering, or giving away a narcotic drug not pursuant to a written order in violation of 26 U.S.C.A § 4705 (1967). Appellant contends that the trial court committed reversible error in allowing a government agent to testify about a conversation between appellant and a third person *371which the agent overheard through the use of an electronic transmitter hidden on that third person.1 We affirm.
The facts of the case may be briefly stated. Government Agent Seibert and an informer, Emmet Gantt, drove together to an apartment house. Gantt was outfitted with an electronic transmitter, given twenty dollars, and sent into the apartment building. He was admitted into one of the apartments by an unidentified man. Gantt woke up appellant and engaged him in conversation concerning the purchase of narcotics. Gantt purchased some narcotics from appellant and injected part of them into his body at that time. He returned to Agent Seibert without the money but with one capsule of heroin. The conversation between Gantt and appellant was overheard by Seibert through the electronic receiver and transmitter. At appellant’s trial, Gantt and Seibert both testified to the conversation. Appellant’s counsel objected to Seibert’s testimony (but not that of Gantt) contending that the evidence, if admitted, would result in a violation of appellant’s constitutional rights under the Fourth Amendment. The trial judge first excluded, but then admitted the testimony.
There is no merit to the contention that this constituted reversible error. The testimony of Gantt as to the conversation with appellant in the apartment to which Gantt was lawfully admitted was clearly admissible. See Hoffa v. United States, 1966, 385 U.S. 293, 87 S.Ct. 408, 17 L.Ed.2d 374; Lewis v. United States, 1966, 385 U.S. 206, 87 S.Ct. 424, 17 L.Ed.2d 312. And it remains the law that testimony regarding the content of conversations between informers and suspects overheard by government agents by the use of electronic devices under circumstances such as those in this case are admissible into evidence. See Osborn v. United States, 1966, 385 U.S. 323, 87 S.Ct. 429, 17 L.Ed.2d 394; Lopez v. United States, 1963, 373 U.S. 427, 83 S.Ct. 1381, 10 L.Ed.2d 462; On Lee v. United States, 1952, 343 U.S. 747, 72 S.Ct. 967, 96 L.Ed. 1270; Long v. United States, 5 Cir., 1967, 387 F.2d 377 [Nov. 10, 1967]; Beatty v. United States, 5 Cir., 377 F.2d 181, rev’d. on other grounds, 1967, 389 U.S. 45, 88 S.Ct. 234, 19 L.Ed.2d 48; Hurst v. United States, 5 Cir., 1967, 370 F.2d 161.
These cases are undisturbed by the Supreme Court’s very recent decision in Katz v. United States, 1967, 389 U.S. 347, 88 S.Ct. 507, 19 L.Ed.2d 576, where the Court held it to be an unreasonable search and seizure for federal agents by means of an external (non-wiretapping) electronic device to listen to and record the defendant’s end of telephone conversations made from a public booth. Indeed, the Court specifically expressed continued approval of the principle that “what a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection. See Lewis v. United States, 385 U.S. 206, 210, 87 S.Ct. 424, 427, 17 L.Ed.2d 312.” Katz v. United States, supra, 389 U.S. at 351, 88 S.Ct. at 511, 19 L.Ed.2d at 582. The present case presents an entirely different situation from the one in Katz and that decision does not require a different result from that reached by the trial judge. See Katz v. United States, supra, 389 U.S. at 362, 88 S.Ct. at 517, 19 L.Ed.2d at 589 (opinion of White, J., concurring).
Affirmed.
. Appellant also charges error by the trial judge in allowing the government agent to remain in the courtroom after the Rule (F.R.Orim.P. 30) had been invoked. This action is within the sound discretion of the trial judge and no abuse of that discretion is shown here. See Del Cristo v. United States, 5 Cir., 1964, 327 F.2d 208; Portomene v. United States, 5 Cir., 1955, 221 F.2d 582; Bostwick v. United States, 5 Cir., 1955, 218 F.2d 790.