Features: 1. Automatically activated when reversing gear is engaged 2. The closer the obstacle is, the faster the alert beeping frequency is to indicatethe safety zone, caution zone and danger zone 3. Having 2/4/6/8 ultrasonic sensors selectable . 4. Voice report optional. 5. Blue background digital LCD Display screen. 6. Ajustable volume: ON/OFF 7. Dynamic digital LCD display to indicate different distances as well as orientation of the obstacle (front or back) 8. Dynamic sketch indicater of the working sensors. 9. Exact distance display STOP reminder. Technical parameters: 1. Operating voltage: 12V DC (24V optional). 2. Operation current: 20mAh ~ 200mAh. 3. Sensor installation height: 45 ~ 60cm 4. Detection distance: 0.2 ~ 2.0m. 5. Ultrasonic frequency: 40kHz. 6. Operating temperature: -40C ~ +85C 7 Beep volume: 80 ~ 100dB (at 30cm distance)