Air assist primary stage, activated by a foot pedal, for rapidly raising the mounting head to the load. Second stage, activated by a hand pump, provides precise control when raising the load. Release knob gives precise control when lowering the load. Big, easy-to-grip knobs make mounting head adjustments simple; a safety chain secures the load. Wide leg base with 4" polyurethane swivel wheels that provide stability and easy maneuvering. (Brakes on two of the wheels.) Safety overload system prevents jack from being used beyond its rated capacity. Height in low position, 36"; max. 74-7/8". Tilt forward, 42; backward, 46; either side, 12. 2-year Limited Warranty.