Brownell Air-Powered Boat Lift 8,000 lb Capacity. Air over hydraulic operation allows one person to operate four lifts simultaneously with a standard (not included) manifold. 25' air hose included. Recommended air supply 120 PSI with minimum 20-gallon storage tank. SWL 8,000 lbs per jack. Powered by hydraulic jacks for smooth and easy operation. Safety Pins for added protection. No-flat tires and hand grip for easy mobility. Adjustable base and arm with two arm positions. Full capacity for entire lifting range 27"-59". Capacity at horizontal extension: 8,000 lbs at 10", 6,000 lbs at 14", 4,000 lbs at 18".