66835 Universal Mini Valve Spring Tester for 0-300LB/5LB Increments Valve Spring Fitment This is a general purpose spring tester with a wide range of applications.( 0-300 psi and 0-20 kg/cm2 ) Features 1. 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. 2. Measurement: .