This Air-cooled, 2T 72cc big bore kit consists of a top-quality, Iron cylinder and a 2-ring alloy piston / 10mm wrist-pin design that makes this kit extremely durable and powerful. Perfect fit for a Yamaha Jog, Zuma or Genuine Buddy 50 or Roughhouse 50 looking for more power, on a budget. This cylinder is also available as part of our Stage 2 Buddy 50 Performance Kit (#PKBUD50-2) Stock exhaust studs will fit. But If you want a spare set: Sku: 0500-1035 Replacement Piston Assy #1100-1416 Replacement Gasket Set #1100-1415 Specs: 47mm Bore 10mm Wrist Pin 72cc Displacement Contents: Iron AC Cylinder Alloy Piston Piston Ring x2 Wrist Pin Wrist Pin Clip x2 Head Gasket Cylinder Gasket Fitment: 2T, Air Cooled, Minarelli engines with 10mm wrist pin such as: Genuine Buddy, Rattler, RoughHouse, Yamaha Vino, Zuma, etc. This product is intended for off-road use only.