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(Silver) 4 sensor system, double CPU and advanced chipset for enhanced coverage and detection With Bi.Bi.Bi alarm, the closer, the more rapid alarm Help to prevent dangerous and costly collisions, enhance the safety features with simple installation Help to provide increased safety for passengers, pedestrians and family members who happen to be around the moving vehicle Step by step alarm with LED display