Enclosed, requires separate 24VAC power. Wiring harness with plug for detector included. OPEN only (all LiftMaster operators) or SAFETY/HOLD OPEN only (operators with type B2, T, TS or T1 control wiring) when vehicle passes over loop wire. Requires a loop of wire embedded in the ground to connect to the detector. Requires 2-wire output connection to door operator and 24VAC power.