Features: 1) 2 front sensors detect the front barrier while STOP car, 4 back sensors detect the back barrier while PARKING car. 2) Graded tone buzzers and tricolor lamp indicate distance between the car and the barrier. 3) Sensors can be installed without drilling holes in the car. Size 35.0 x 25.0 x 5.5 Centimeters Packaging 10 Package Size 59.0 x 35.5 x 25.5 Centimeters Package Weight 9.8 Kilograms Delivery lead time 10 days Minimum order 200pcs Supply ability 30,000pcs/month