INTENDED USE: Heavy duty truck, heavy construction and agricultural equipment maintenance garages. FASTJACK? mechanism raises the jack?s lifting saddle to the load in one pump stroke. FEATURES: U.S. PATENT NUMBER: 7,055,801 B2 Chromed ram and dust seals prevent hydraulic contamination. Safety bypass and overload systems prevent cylinder damage and prevent the jack from being used beyond the ASME/PASE load-limiting standard. Air pump models can also be operated manually. Includes the FASTJACK? feature which raises the jack?s lifting saddle to the load with one pump of the ?T? handle. Locking release lever secures handle in the vertical, 45 degree or horizontal position to lower the load on all models.