If your garage door spring has broken, this P528 is a replacement extension spring for heavier one-piece or tilt-up style doors. It’s a plug-end style spring (requires separate S-hooks or W-hooks to connect to the door bracket and rear track). Each spring is 28 inches long over the coils, with a 1-5/8 inch outside diameter, made from 0.207-inch (No. 5) steel wire. The initial tension is between 135-145 lbs. It can stretch up to 22 inches safely during operation. Typically, two springs (one on each side) are used for doors weighing between 105 and 175 lbs. For heavier doors (200-350 lbs), you’d use four springs (two per side). Always replace extension springs in pairs for balanced operation. Important: Garage door springs are under high tension; installation can be dangerous if you’re not experienced. Consider hiring a professional.
