delivered the opinion of the Court.
The question presented by this appeal is, whether State Farm’s policy insuring Lewellyns truck provided coverage *544where a borrowed mobile welding rig wbicb Lewellyn was palling behind his track, came loose and damaged an aatomobile and injured a passenger therein. The Chancellor held there was no coverage, and we agree.
The pertinent provisions of the policy are to be foand in the definition section, relating to insaring agreements 1 and 2; and in the insaring agreement 2, relating to non-owned aatomobiles. A non-owned aatomobile is defined as including a non-owned trailer.1
A trailer is defined as one designed for ase with a private passenger aatomobile and not ased for business parposes with other than passenger aatomobiles.2
The non-owned aatomobile insaring agreement affords limited coverage to loss dae to a non-owned trailer in the event it is a non-owned trailer as defined in the definition of the policy.3
Since it is stipalated the trailing welding rig was non-owned, was not being palled by a private passenger or a atility aatomobile, and since the welding rig was a trailer designed for ase for basiness parposes with other than a private passenger aatomobile, there is no coverage afforded by the policy. For cases defining the mobile *545welding rig as a trailer, see Waddey et al. v. Maryland Casualty Company, 171 Tenn. 112, 100 S.W.2d 984, 109 A.L.R. 654; Blue Ridge Insurance Company v. Roy L. Haun et al., 197 Tenn. 527, 276 S.W.2d 711.
The second contention, that there was a waiver of the policy provisions mentioned, or that the Insurance Company is estopped to rely thereon, must be denied.
These defenses, waiver and estoppel, are based on a letter written by the Company to Lewellyn wherein it pointed out certain policy provisions under which it contended it was not liable under its policy. However, since in this same letter,4 the Insurance Company reserved every defense available to it under its policy, and there is no showing whatsoever of any harm or injury to the appellant because of the letter, the defenses are not good. See 45 C.J.S. Insurance sec. 707, p. 677.
*546The assignments of error are overruled and the decree of the Chancellor is affirmed.
Burnett, Chief Justice, and Dyer, Chattin and Ceeson, Justices, concur.“Non-Owned Automobile — means an automobile or trailer not (i) owned by, (ii) registered in the name of, or (iii) furnished or available for the frequent or regular use of the named insured, his spouse, or any relative of either residing in the same household, other than a temporary substitute automobile.”
“Trailer — means a trailer or semitrailer not so described if designed for use with a private passenger automobile and if not (1) a passenger trailer, (2) a trailer used for business purposes with other than a private passenger automobile, or (S) a trailer used as premises for office, store or display purposes. This insurance does not apply, under coverages C and M, to a house trailer while used as permanent living quarters.”
“* * * (3) coverages D, D-50, F, G and H applies to loss to a non-owned automobile provided (a) such automobile is a private passenger or utility automobile or a trailer as defined herein * * *”
“May 19, 1967 Mr. Joe R. Lewellyn
3709 Graves Road Memphis, Tennessee 38116
CERTIFIED MAIL-RETURN RECEIPT REQUESTED
Re: Your File # 42-396-028
Your Policy # 1726 962-C01-42A
Dear Mr. Lewellyn:
This letter is relative to the accident which you had no April 22, 1967, when you were driving a 1967 Chevrolet pickup truck and when you were pulling behind such pickup truck a welding rig belonging to the T. C. Beardin Company. This accident occurred near the intersection of Springdale and Eldridge here in the city of Memphis, Shelby County, Tennessee.
As a result of the accident in question, a claim was presented against you by Mrs. John W. Moore, 1257 Capitol, Memphis, Shelby County, Tennessee, because of personal injuries and also a property damage claim has been presented because of damage to the Moore vehicle.
I refer you to your insurance policy # 1725 962-C01-42A and specifically to the section dealing with Definitions. — Insuring Agreements I and II and first of all to the definition of NON-OWNED AUTOMOBILE — means an automobile or trailer not (1) owned by, (2) registered in the name of, or (3) furnished or available for the frequent or regular use of the named insured, his spouse or any relative of either residing in the same household, other than a temporary substitute automobile. As you can see, a definition of a non-owned automobile includes therein a non-owned trailer.
*546Therefore, I call your attention to the definition of trailer contained in the section Definitions — Insuring Agreements I and II wherein it states: ‘means a trailer or semi-trailer not so described if designed for use with a private passenger automobile and if not (1) a passenger trailer, (2) a trailer used for business purpose with other than a private passenger automobile,’
Our investigation of this matter has revealed that the trailer which you were using when this loss occurred is definitely a non-owned trailer as it was owned by the T. C. Beardin Company. Also, our investigation has further revealed that this trailer was not a trailer designed for use behind a private passenger automobile and secondly you were using the trailer for business purposes with other than a private automobile as the pickup truck behind which you were pulling the trailer is not a private passenger automobile, but rather is a utility automobile.
For the above reasons and any other reasons now in existence or that might develop at a later date, we must expressly deny any payment under the bodily injury liability, property damage liability, and collision coverage of your policy, as well as all other coverages. ~We cannot be held liable for any defense or [sic] any lawsuits brought against you by the adverse parties or will be responsible for any judgments rendered against you. The defense and costs of any lawsuits filed against you and the payments of any judgments will be your personal responsibility.
Yours very truly,
/s/ Robert B. Gwyn Robert B. Gwyn
Resident Claim Superintendent.”