The BrakeBuddy takes the entire weight of the towed vehicle off the motor coach's overburdened brakes. The BrakeBuddy greatly reduces your stopping distance by reducing the added weight of the towed vehicle for a safer more secure stop. The BrakeBuddy is completely self-contained. The system plugs into the cigarette lighter or accessory outlet of the towed vehicle to power the internal air compressor. The BrakeBuddy® was designed and built as an auxiliary braking system to operate in conjunction with the existing braking system in your towed vehicle..