AFF Air/Hydraulic Bottle Jacks are for use in lifting heavy duty trucks, construction equipment,and even heavy farm equipment. Centered pumps and rams with heat-treated pistons for balance and easy positioning. Saddles are machine-hardened steel. Each operates at 90-180 PSI and is factory pre-tested to 150% of its rated capacity. Also includes a safety bypass system to prevent possible damage from ram over-extension.