TRAILER MATE POWER PACK by POWERWINCH/CAREFREE OF COLORAD Trailer Mate Power Pack is a power supply designed specifically for 12-volt trailer winch and the Marine Industry. The Powerpack consists of a regulator mounted in a self-contained waterproof battery box. A lead acid garden tractor type battery (not supplied) and the 7-pin RV socket found on most tow vehicles power the winch and Powerpack. This eliminates the need and costs of wiring the tow vehicle to power the winch.