Craftsman 1/2hp Chain Drive Model 139.53975SRT1 Garage Door Opener Powerhead. This Craftsman garage door opener has a 41A5021-2F circuit board that has a. This opener is compatible with the above listed garage door openers that have photo eyes to operate the door. It is compatible with any circuit board that has a.It is compatible with 971LM and 973LM remotes and 976LM keypad. Compatible with any LiftMaster, Craftsman, Chamberlain openers with a RED learn button that are chain driven. Remotes, rail, chain, and photo eyes are not included. Opener will hook up to any T style or square style rail with a chain. IF YOUR ARE NOT SURE IF THIS OPENER IS COMPATIBLE PLEASE MESSAGE US BEFORE PURCHASING THE ITEM. PLEASE CHECK OUT OUR OTHER ITEMS AND FEEL FREE TO MESSAGE US AT ANY TIME WITH ANY QUESTIONS. The item "Craftsman 1/2hp Chain Drive Model 139.53975SRT1 Garage Door Opener Powerhead" is in sale since Thursday, February 7, 2019. This item is in the category "Home & Garden\Home Improvement\Building & Hardware\Garage Doors & Openers\Opener Systems". The seller is "shopatals" and is located in Rochester, New York. This item can be shipped to United States, Canada.