This specially designed door opener is mounted to the wall beside the garage door. It frees up ceiling space that can now be used for maximum storage. The powerful DC motor provides ultra-quiet operation, along with smooth start and smooth stop to reduce the noise of the garage door as it opens and closes. What's more, this unique system offers the added option of a battery backup system to let you get in and out of your garage, even when the power is out.

• http://liftmaster.com/pdfdocs/114A3268.pdf

Model 3800 offers an ultra-quiet, space-saving, wall-mounted design. 

Specially designed for garages and unique applications that don't allow for a traditional garage door opener, such as garages with very low, cathedral or obstructed ceilings

INSTALLATION FEATURES

• Wall-Mount Installation - mounts on the left or right side of door. No rails to hang, it simply mounts on the wall and attaches to the garage door torsion bar. Unit requires an electrical outlet within 6 feet.
• Patented Absolute Positioning Technology - the newest technology in garage door openers, our patented design allows the electronic limits to be extremely accurate, even after a power failure.
• The Smart Garage Door Opener® - lets you electronically program additional remotes or a keyless entry from the motion-detecting control panel or the powerhead.
• 6-Foot Power Cord - makes connecting to a power source easier than ever.
• Push Button Limit Settings/Automatic Force Sensing - Auto-force feature constantly monitors garage door system and adjusts forces to temperature fluctuations, floor height and door track movement.

INCLUDED ACCESSORIES

• Motion-Detecting Control Panel
• 1 designer burled walnut 3-Button Security+® Remote Control
• Remote light

SAFETY FEATURES

• Power Lock - Once the garage door goes down, it's securely locked with the power lock. Similar to a deadbolt, it ensures the door cannot be forced open.
• Includes The Protector System® - projects an invisible light beam across the garage door opening and automatically reverses the door if anything interrupts the beam while door is going down               
• Manual release handle in case of power failure

WARRANTY

• Lifetime warranty on motor
• 5 year parts warranty
• 1 year battery warranty