This 60mm Big Bore Kit by Send It Kartel will take your Grom, Monkey, motorcycle, quad, scooter, whatever it might be that you're upgrading to that next level! Your buddies will be jealous when you're pulling away from them with all of the extra power you will be gaining. The kit comes with everything to swap out your cylinder and piston. It comes with the 60mm aluminum cylinder block, 60mm high compression piston, piston rings, wrist pin, circles, and gasket set. This kit will take your 125cc Grom or Monkey to a stump thumping 169cc. Here at Send It Kartel, we will walk you through the steps it takes to replace the parts on your project. We are a family owned business that aims to please. Thank you for putting your trust in us.