... as well as obstacle orientation,-Components Included: 4 sensors/ECU/ buzzer/buzzer cable/power cable,-Audible alert, the closer the obstacle, the ... ,-Max Detect Range: 1.5m/Custom-made,-Transmitting Frequency: 40kHZ,-Buzzer Sound Pressure Level: >80dB,-Detect Angle: Horizontal 120°, Vertical 60 ... when reverse gear is engaged, Excellent Quality car parking aid with reasonable cost