High-Performance 4-Stroke Race PistonFeature fully boxed-style forging for ultimate strength, minimizing friction, durability, power, and weight reductionFull radius dome designs maximize quench while eliminating hot spots that promote detonationInternal bracing maximizes durability while decreasing friction in the pin assemblyForgings come standard with skirt coating which reduces friction, which in turn reduces heatIncludes a DLC (Diamond-Like Carbon coating) wrist pin; this technology has been proven and used because of its high resistance to abrasive wear, which extends the service life and reliability under extreme conditionsKit includes piston, wrist pin, rings, and circlipsMade in the USA13.5:1 compression ratio for '04-'05 YFZ450 and '09-'20 YFZ450R. 13.75:1 compression ratio for '06-'20 YFZ450 fuel injected models.