Sears Craftsman Liftmaster Garage Door Monitor Additional Sensor 916LM

Tells you if your garage door is open or closed

Security for the largest door to your home

Great convenience and peace-of-mind

Works with any garage door

Monitors up to 4 garage doors (works with the 915LM)

When light flashes red, door is open

Fast, easy installation; no tools needed

Signals to any room in the home