The Performance Tool W80570 Valve Lapper is a durable and reliable tool for engine maintenance. Featuring heavy-duty rubber suction cups and a hardwood handle, this valve lapper is built to last. Use with lapping compound (not included) to lap valves to match valve seats, improving engine performance and reducing the risk of damage to the valves. This valve lapper comes in two sizes, 5/8 and 13/16, providing a versatile and convenient tool for a range of valve sizes. Its small size makes it easy to use and maneuver in tight spaces, making it an essential tool for any mechanic or DIY enthusiast. Simply attach the suction cups to the valve and rotate the handle back and forth to lap the valve to the proper seat.