36645R.S Genie Screw Drive Coupler
The Genie screw drive coupler is used with the Genie AC Screw Drive Openers listed below; The Screw Drive Coupler connects the operator motor head to the screw drive rail. When the motor on your opener is running and the screw drive is not turning the coupler may be bad. 
Use With Opener Models: 2562, 2564, 2568, 3062, 3064, 4062, 4064.
Use With Opener Models:  Powerlift 900, GPower 900, PowerMax 1200, TriloG 1200, Excelerator 1000, Excelerator II.
Use With Opener Models: PowerMax 1500, MachForce, MachForce Connect, TriloG 1500.