LED parking sensor,Rear Parking Sensor system R03 Product Features:High sensitivity ultrasonic detector Intellectual step-by-step voice-directed alarm system Safer parking operationNumber of sensors: 4 pcs Color of sensors: various color by your choice Alarm mode Stage DistanceAwarenessDisplayAlarm sound1>2.0mSafeSilent22.01.6mSafe2.01.6Silent31.51.1mAlarm1.51.1Slow ringBiBiBi41.00.7mAlarm1.00.7Normal ring (Bi Bi Bi)50.60.4mDanger0.60.4Fast ring (Bi, Bi, Bi)60.30.0mDanger0.30.0Continuously ring (Biiii) Stage Distance Color 1 >2.0m Extinguishing 2 2.00.9m Green 3 0.80.5m Yellow 4 0.40.0m Red