1Engine Valve Grinding Tool: The engine cylinder head valve lapping tool provides the easiest and most efficient way to lap your valves, restore the running effect of the engine. 2Function: Grind the valve to make the port and the valve plane contact closer, valve leakage will cause insufficient cylinder pressure, the engine lack of cylinder work, weakness. 3Material: Made of carbon steel, it has high strength and rigidity, and can withstand high temperature, high pressure, impact, lubrication difficult work requirements. 4Perfect Configured: With speeds up to 3000 rpm, a hose bore of 10 mm, a 1/4in air intake, and a 3.53CFM air consumption, work efficiently and quickly. 5Package Includes: The package includes four rubber suction cups in sizes 20mm 30mm 35mm 45mm and a toolbox for the perfect storage of the grinder.