The Giant Pumps 12308 replace a worn or leaky piston backup ring inside unloaders. It is compatible with pressure-actuated unloader models 22760A, 22760APM, 22760A-SS, 22760L, 22760LR, and 22760-01. This is a genuine OEM part. Designed to ensure a proper fit, material compatibility, and functionality with the recommended unloader models.