4 pcs valve grinder:2 pcs yellow+black & 2 pcs blue + black yellow+black valve grinder: ACCURATELY SEAT VALVES:TheValve Hand Lapping Grinding Tool Kit 2-Piece Set-Dual-End Suction Cup Lap Stick,1-1/8 inch,1-3/8 inch,5/8 inch,3/16 inch Inch helps you properly match valve seats during an engine top-end rebuild; These tools include dual ends with oil and UV-resistant synthetic rubber cups that help you put the finishing Press on your tune-up VARIOUS APPLICATIONS:Suitable for any clean,flat surface of a lawn mower,chainsaw,or small or large engine car or other vehicle with 5/8-inch,13/16-inch,1-1/18-inch,and 1-3/8-inch (1.6cm,2.1cm,2.9cm,3.5cm) valves; 8.9-inch and 8.3-inch (22.6cm and 21.1cm) overall lengths make these tools useful for even installing and removing recessed fixtures or hard-to-reach mini-flood light bulbs GRIP COMFORTABLY:6.75-inch (17.1cm) long handles for ultimate control,less user fatigue,and more productivity; 8.9-inch and 8.3-inch (22.6cm and 21.1cm) overall lengths EASY TO USE:Clean all carbon deposits off valve and wipe down each valve,install valve in valve guide,press correct size suction cup firmly onto of valve,and lightly spin tool handle between palms of your hand (as if trying to start a fire) until a suitable is obtained; We recommend placing valve lapping/grinding compound (not included) on valve seat or valve surface (keep compound off the top surface of the valve to proper suction) blue + black Valve Lapper: Sizes: 15mm - 19/32 inch 20mm - 25/32 inch 25mm - 31/32 inch 30mm - 13/16 inch Length - 225mm Place valve lapping compound on valve seat or valve surface as directed by compound instructions. Install valve in to valve guide. Press correct size suction cup firmly on to off valve. Spin valve lapper tool handle between palms of the hand until a suitable is obtained Color:yellow+black & blue + black Material:plastic+wood & plastic Package Contents: 4 x valve grinder Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.