Features:Three wave and seven wave bands standard display. Connectable to rearview mirror from original factory. Different voice alarm. Set four special supersonic sensors, detect all directions. Technical parametersOperating Voltage:12V DC(24V available) Operation current: 20mA~200mA Sensor installation height: 45~60cm Detection distance: 0.2~1.5m Ultrasonic Frequency:40 KHZ Operating temperature: -40°C ~ +85°C Beep volume: 80~100dB(at 30 cm distance)