ePathChina&reg; Dual CPU Car/Truck/Vehicle Mini Car LED Display 4 Sensors Kit Reversing Parking Sensor/Backup Sensor/Reversing Sensors System Radar Buzzer System,Three Stage Bi-Bi Sound Alarm(White) This car rear parking assist system help you be safe while parking. It helps you avoid bumping into other cars, objects, and even children by detecting the distance between your vehicle and rear obstructions. It does this by using ultrasonic sensors that send wireless signals from a transmitter control box to the display unit. Easy to install.Intuitive and easy to use.Protect your vehicle and others.System automatically activates when reverse gear is engaged. Dual CPU system.Step-up alarm.Intelligent anti-interference analysis. Obstable of orientation indication. Operating temperature: -40 degree to 80 degree.Sensors installation height: 50cm - 70cm.