69 Pa. Stat. § 1308
Retail installment sales negotiated and entered into by mail or telephone without personal solicitation by a salesman or other representative of the seller, where the seller's cash and deferred payment prices and other terms are clearly set forth in a catalog or other printed solicitation of business which is generally available to the public, may be made as hereinafter provided. All of the provisions of this act shall apply to such sales except that the seller shall not be required to deliver a copy of the contract to the buyer as provided in section 307, and, if when the proposed retail installment sale contract is received by the seller from the buyer, there are blank spaces to be filled in, the seller may insert in the appropriate blank spaces the amounts of money and other terms which are set forth in the seller's catalog which is then in effect. In lieu of the copy of the contract provided for in section 307 the seller shall, prior to the due date of the first installment, furnish to the buyer a written statement of the items inserted in such blank spaces.
69 P.S. § 1308