Backup horn output of up to 105DB,Voltage Range of 12-36 Volt Vehicles DC system.Preferably your reverse backup bulb wire. Reversing alarm used high quality stainless steel power and ground connection terminal Auto warning alarm bracket with slotted holes and mounted anywhere in your heavy-duty vehicle. for Trucks Van Freight Car Lorry Heavy Vehicles. Our backup alarm is very easy to install, you just need to splice a wire from the positive screw terminal to the power wires of the reverse light or a reverse switch installed on the dashboard, then splice a wire to the ground(Negative wire). Each backup warning alarm conforms Reverse polarity protected backing up horn and activation when reverse lights are on (must wire to them). Add peace of mind to your vehicle when backing up. Avoid dangerous situations and alert people around you that you are reversing. Waterproof housing with epoxy embedded electronics. Reverse polarity protected. Easy installation,come with in-built bracket and wired stud connection points. Mainly used for car,excavators,construction machinery,special vehicles,parking and a of large vehicles container vehicles reminder. Voltage:12-36v Rated Current:0.1-0.8(A) Power Output:15W Volume:105DB Material:ABS colour:Black Package Contents: 1 x Reversing Alarm Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.