Alarm in three-stage sound: BiBiBi Digital LED showing the distance LED display with three colors ( red, yellow, and green) Automatic detecting obstacles once reversing gear is activated Wireless module is optional Operating voltage: 10.8 to 15V Supply voltage: plus 12V more or less than 12V DC, 24V is available Power: 2W ( maximum) Ambient temperature: -30 to 70° C Storage temperature: -35 to 85° C Buzzer volume: -80dB 2, 4, 6, 8 sensors are available to satisfy full needs of customers