"The Black Widow Wheel Dolly and Positioning Jack Four Pack helps to maneuver vehicles, ATVs and UTVs around garages, body shops, showrooms, parking garages and other level-surfaced area where space might be limited. Constructed of reinforced steel, each jack dolly has a black powder-coat finish and is designed with a hydraulic mechanism that allows the wheels to compact inwards while they lift the tire up to 4.25"" off the ground. Each positioning jack can support up to 1,500 pounds per wheel, and two are required to move a vehicle by non-braking wheels. A safety locking pin holds the dollies in lifted position while moving, and foot pedals on each unit have a locking hook for added safety. Integrated carrying handles makes them easy to move around your space."