Norco Professional Lifting Equipment - The 76520B Heavy Duty 20 Ton Standard Bottle Jack is intended for heavy duty truck, agriculture, construction, mining, mobile home, oil field, automotive, and marine applications where lifting, pushing, spreading, bending, pressing, or straightening are required. It features a 50% safety overload factor, a State-of-the-art design that reduces repair time, a safety oil by-pass system prevents the ram from being overextended and causing damage to the cylinder, and a longer wear life due to internally machined oil passages, smooth bearing surfaces and close tolerances.