-Self-test function activated when reversing; -Beeping warning & LED digital display; -Display in green,orange and red; -Left and right obstacle display; -Supply voltage: 12V±2V (DC) -Max power: <5W; -Working temperature: -40℃~+80℃; -Display distance: 2.0m~0.3m; -Alarm distance: 1.5m~0.4m; -Alarm Voice: 80dB.