Specifications: 1.Measuring the distance by radar 2.Alarm by three step Bi-Bi sound 3. 4 rear sensors are available 4.Full-weather design, un-affected by wind, ice, snow & rain 5.All kinds of sensor colors and styles are available 6.High quality and easy to install Technical Parameters: 1.Rated Voltage: 12V DC 2.Operating Range: 10.5V-16V DC 3.Rated Current: 50mA- 180mA 4.Detecting Distance: 0.3- 2.0m 5.Ultrasonic Frequency: 40KHz 6.Display Working Temperature: -30-+70- -------------------------------------------------------------------------------- ALARM SOUND Stage Distance Area Sound Digital display 1 160-200cm Safe Mode No sound 1.6-2.0 2 100-159cm Safe Mode Bi---Bi---Bi 1.0-1.5 3 40-99cm Alarm mode Bi-Bi-Bi 0.4-0.9 4 0-39cm Danger Mode Bi------ 0.0