Liftmaster S505AL Monitored Small Profile Resistive Edge with aluminum channel 5ft Meets 2016 UL 325 requirements Edge sends signal to stop and/or reverse operation when sensing obstructions Fast, easy to install Mounts vertically or horizontally Compatible with Wireless edge kit LMWEKITU, Transmitter LMWETXU and LiftMaster Gate Operators with Monitored Safety Inputs