4sets Motorcycle Accessories Cylinder Bore STD~+100 Size 67 67.25 67.50 68mm Piston Rings Full Kit For YZF-R6 YZF-R6R R6 Piston and rings set designed for motorcycle engine rebuilds.Maintains compression of the air-fuel mixture within the cylinder.Helps regulate engine oil from the crankcase entering the combustion chamber.Transfers heat from the piston crown to the cylinder block for efficient cooling.Reduces direct between the piston and cylinder wall to minimize wear.Includes 4 sets with bore sizes of 67mm, 67.25mm, 67.50mm, and 68mm.Fits YZF-R6 and YZF-R6R R6 models.Direct replacement for components. Compatibility Disclaimer: This is an aftermarket replacement part.Any brand names or model designations mentioned are used solely for the purpose of demonstrating compatibility.