The right tools for the job make a project go smoother and quicker. Servicing a viscous fan clutch is one of those jobs. The Powerbuilt 10 Piece Fan Clutch Wrench Master Set is designed to remove threaded-on viscous fan clutches on Ford, Chrysler, Jeep, and some imported vehicles with these strong heat-tempered steel fan clutch wrenches. The larger wrench keeps the water pump shaft from spinning while you loosen the fan clutch nut with the appropriate smaller wrench. Wrenches are 1/2 inch square drive, allowing the use of breaker bars and ratchets. The wrenches' black finish is strong and durable for a lifetime of use. The set comes in a sturdy blow-molded hard case with professionally written usage instructions and photos. All Powerbuilt installer kits meet or exceed ANSI standards.