1. Scope of application Work voltage is DC:9-12V, the host of maximum current is less than or equal to 15mA product overview This product by sending and receiving ultrasonic signal changes ahead of motion obstacle detection, the detection range of a moving distance or close to set the trigger switch signal start, can control the external circuit to perform acousto-optic alarm, or switch to control; Description:working voltage:9-15Vworking frequency40KHZ Static current3maInduction distance0-8m The two LED lights flicker alternately, indicating that the ultrasonic is sent to receive normal. Then the green LED indicator lights will flash up, indicating that the system has entered the normal working state, and the green light is extinguished without induction.