Features: 1.Fittment:This is a general purpose spring tester with a wide range of applications.( 0-300 psi and 0-20 kg/cm2 ) 2.Material: This product is made of high-quality stainless steel, aluminum alloy and rubber, which is durable and has a longer service life. 3.Mini Valve Spring Tester:The Mini Style Valve Spring Tester is a quick and easy way to check your valve spring. It can be used in a vise or an arbor press. Reads up to 300 pounds in 5 pound increments. A must-have item when rebuilding cylinder heads, upgrading camshaft, or when doing any valvetrain work. Interchangeable Manufacturer Part Number: 66835. .