1. Scope of application The operating voltage is DC: 9-12V, the host maximum current is less than or equal to 15mA Product Overview This product by sending and receiving ultrasonic signals changes before detecting movement obstacles, the range of detecting moving distance or close to set the trigger switch signal start , can control the external circuit to make acoustic-optical alarm or switch to control; Description: Working voltage: 9-15V Working frequency: 40KHZ Static current: le; 3ma Induction distance: 0-8m Two LEDs flash alternately, indicating that ultrasonic is sent to receive normal. Then the green LED will flash to indicate that the system has entered the normal working state, and the green light will turn off without induction.