This torsion spring is constructed of steel and comes with a red color code on the winding cone end. It is a right wind spring and its left wind partner is model number GD 12229. At the opposite end of the winding code, a stationary cone is also included with this spring, both cones constructed of diecast metal. This torsion spring provides lifting force for heavy garage doors and must be selected by the spring’s dimensions, rather than the door’s weight. This torsion spring is a regular duty spring with an estimated lifetime rating of 10,000 cycles. These torsion springs are used to repair damaged or worn garage door springs that are found directly above the door and mounted to the header.