1,Self check when power on, 2,Alarm by 3 step bibi sound 3,LED digital display 4,1 year warranty ... 5,4 sensors LED(4)Speaker Warming Led Display Car Parking ... sensor, auto-start when back up.Obstacle distance in digital displayed on “8.8” format and dual 7- ... weight: 14kg Hot sale,1 year warranty,LED Digital Display Voice Parking Sensor System,4 sensors,