Car Security System Max Detect Range: 1.5m/Custom-made, Transmitting Frequency: 40kHZ, Buzzer Sound Pressure Level: >80dB, Car Security SystemFeatures:-E means cheap ... Included: 4 sensors/ECU/ buzzer/buzzer cable/power cable,-Audible alert, the closer the obstacle, the faster the beep frequency,-Rated ... °,-Audio Warning:5 status, High quality and reasonable price car security system