Automatically engages as soon as you place your car into reverse. Show distance by multi-functional ultra-thin VFD display,Bi Bi voice warning. Support safe HUD (head up display) mode:rotate the display face to car windshield and choice HUD mode to read the distance from windshield. Embedded detector sensors (which requires installation into your rear bumper). High-tech processing,- Omnidirectional detector sensor,Beautiful linetype figure.