DOES NOT WORK WITH ALL GARAGE DOORS! PLEASE BE SURE TO MAKE SURE IT WILL WORK WITH YOUR APPLICATION BEFORE YOU BUY. BUYER RESPONSIBLE FOR ORIGINAL SHIPPING PLUS ALL RETURN SHIPPING COSTS. ONLY WORKS WITH FRONT A TORSION SPRING SYSTEM AND STANDARD TRACK. DOES NOT WORK WITH LOW CLEARANCE TRACK, WAYNE DALTON TORQUE MASTER OR EXTENSION SPRING SYSTEMS.Liftmaster 3800 RJO3800DC Motor Residential Jackshaft Opener • Powerful 24V DC motor provides ultra-quiet operation, along with variable speed smooth start and smooth stop• Easy wall-mount installation means no rails to hang• Auto-force feature constantly monitors garage door system and adjusts forces to temperature fluctuations, floor height, and door track movement• The Smart Garage Door Opener® lets you electronically program security codes from the Smart Control Panel® or the powerhead• Enclosed gear case provides continuous lubrication and protection for longer life and smoother operation• A 6-foot power cord makes connecting to a power source easier than ever• New optional Alternate Power Source (580LM) is a safe, permanent option to power the 3800 when an outlet is not within 6 feet; UL approved• Remote light delivers 200 watts of light with adjustable light time delay• Meets all UL325 requirements SAFETY & SECURITY FEATURES • The Protector System® safety sensors project an invisible light beam across the garage door opening and automatically reverse the door if anything interrupts the beam while the door is going down• Sensing technology will stop the door from closing if contact is made with a person or object• Opener light turns on automatically when The Protector System"s infrared beam is broken• Security+® rolling code technology assures a new code is sent every time the remote control is used• Manual release handle in case of power failure WARRANTY• Lifetime motor warranty • 5-year parts warranty