J 50 11 L5 Liftmaster Garage Door Opener-Installation Instructions -Connecting Chain and Sprocket (fits over your 1" garage door shaft)*Transmitters, keypads and safety equipment sold separately on site. Purchase your safety equipment and accessories separately: CPS-L photo protective beams, 658202 or 658302 Pneumatic safety edge kits. Transmitters 371LM, 372LM, 373LM or 333LM. Keypad 377LM. Always use a additional safety device when operating your door from a remote control transmitter or when your garage door is operated from a push button that is momentary contact close.