Glixal ATMT1-008 Performance Big Bore Cylinder Kit GY6 80cc 47mm for 139QMB ATV Scooter Moped Go Kart 1.Inner Diameter of Cylinder: 47mm 2.Outer Diameter of Piston Pin: 13mm 3.High Quality Durable Piston Rings 4.Include Cylinder,Piston,Piston Ring,Piston Pin,Piston Pin Clip,Valve Oil Seal,Gaskets,Tensioner Gasket,Exhaust Gasket,Intake&Exhaust Studs,Exhaust Nut 5. High Performance Upgrade 47mm Cylinder Rebuild Kit for GY6 49cc 50cc 60cc 80cc engine