Car Reverse Sensor System 4 Sensors Digital Display Colorful Warning Bar Buzzer Alert Vehicle Backup Parking System Silver Item Type: Car Reverse Sensor System Material: ABS Working Voltage: DC 9-15V Rated Voltage: DC 12V Number of Sensors: 4 Sensor Diameter: Approx. 22mm / 0.87in Sensor Direction: X, Y, 60 Degree Sensor Installation: Drilling Detection Range: 0.3-2.0M Alert Sound: bibi Three Level Heartbeat Alert Buzzer Volume: 65dB Sound Frequency: 1.6-2.0m 0.5Hz (Slow), 1.1-1.5m 1Hz (Slow), 0.6-1.0m 3Hz (Rapid), 0-0.4m (Continuous) Display: Two Digit Display Distance, Seven Color Glowing Warning Bar Display Cable Length: Approx. 5m / 16.4ft Sensor Cable Length: Approx. 2.5m / 8.2ft