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.