Specifics:Material: AluminumCylinder Bore Size: approx 61mmNumber of ring slots:3Fitment:Fits for Big Bore Haomai GY6 150CC 200CC 61mmPackage includes:1 x Air cylinder,2 x gasket,1 x piston,1 x piston pin,2 x circlips,1 x set of rings，As shown in the figure.Features:Manufactured using the latest computerized technologies derived from GP and F1.Forged pistons are more temperature resistant and longer lasting than cast pistons.These pistons additionally have a piston skirt coating.The piston sets are supplied complete with rings.Airtight function,prevent gas leakage from the top of the piston.This piston ring also achieve the heat dissipation effect.Prevent excessive oil from entering the combustion chamber and to fully lubricate the cylinder wall.Maintain the direction of movement of the piston,so please select the best piston ring for the engine.This kit includes a piston, rings, wrist pin, and circlips.Professional install will be highly recommanded. No installation instruction included.