Used this on a Jeep Wrangler 4 door for 5 years. Still works fine. Universal Air Force One 2nd Vehicle Kit for Supplemental Braking System by Demco. Air Force One is the only air brake system that energizes the towed vehicle's power brakes through a patented process that does not require an electronic vacuum pump. In fact, Air Force One has no moving parts to wear out at all. Air Force One is truly an advance in towed-vehicle braking technology: proportionate, progressive, gentle, user friendly, and fits every towed vehicle with no modifications. Designed for diesel motor homes with air brakes, AFO is the smallest, most effective braking system available. This superior product is perfect to make your trailer towing experience safe and convenient. Designed to meet the highest quality standards, it is second to none in durability and performance. Made using the finest materials, it is sure to serve you reliably for a long time.