LiftMaster Belt Drive Trolley 41B3869-1 Chamberlain Craftsman, Model: 41A3869-1, Tools & Outdoor Store Compatible with Chamberlain, Craftsman and LiftMaster belt drive models that don't use square rail Replaces part 41B3869-3A, 41B3869, 41B3869-1 100% Brand New Authentic LiftMaster Part