Model VRKH01 operates as an electronic eye, emitting a continuous beam of infrared light from the transmitting sensor. When user enters sensor's range, the signal activates the water stream. Built-in delay mode prevents activation by passers-by. A 30-35 second "maximum on" safeguards against accidental or malicious blocking of sensor and sensor burn-out. When blockage is removed, sensor automatically resets. Complete wiring harness furnished with each unit. Sensor is standard on extended bracket only.