Features Application: Offset Valve Tappet Gauge Set & Engine Brake Feeler Gauge Tool is designed for use when setting valve tappets and makes valve lash adjustment easy, Engine Brake Feeler Gauge Tool is designed for help to adjust the gap between the engine brake blades and the engine exhaust valve, providing appropriate clearance to ensure vehicle braking and deceleration Premium Construction: Made from high-quality hardened steel with a corrosion-resistant .