wiseco zuigerset yz250 std w808m06640Endurance and High RPM, Each Piston Is Electra Coated On The Dome, Ring Groove, and Pin Bore, For Maximum Wear Resistance and Protection From Micro Welding, Galling and Detonation, GP Series Parts Generally Have Less Machining On The Outside Armorglide Skirt Coating Reduces Friction and Noise for More Horspower Potential, Kit Includes Piston, Ring (S), Wrist Pin and Circlips, Engineered, Forged, and Bewerkt in de VS.