DESCRIPTION: Precise welded and leak-proof construction. Safety valve prevent the ram from being overextended and causing damage to the cylinder. Arc surface bottom of the steel base to make the load in the center of the piston. Prevent rust with ENP (electroless nikel plating) ram piston, make it smooth, bright, and long life. Double seals in the pump to prevent the oil leak. Longer life than normal screw connection jack due to smooth bearing surfaces and dose tolerances.