6 Sensors 2.5m Wireless Car Parking Sensor , Reverse Sensor System Product parameters Packing Size: 30.5*21*5cm Probe and Accessory: 4 probes & standard configuration Warning Sound: BI BI buzz/human voice Rated Voltage: 12V DC Working Temperature: -35℃～80℃ Description: ◆The parking sensor opens automatically when the reverse gear backs. Detectin range: 0.3-2.5M. All-round detection. Ultrasonic frequency:40±1kHz. ◆The alarm sound can tell the