This is a, top quality, Shindy piston and rings kit for ALL year models from 2007-2012 Yamaha YFM 400 Big Bear IRS (Independent Rear Suspension) ATV. Don't waste your time rebuilding your motor with cheap quality, inferior parts. Build it right the first time with this top quality kit. This kit's made in Japan and includes Teikoku brand rings, which are the rings used by most OEM manufacturers. This kit comes complete with the piston, rings, wrist pin and both circlips. It comes in several sizes, so please be sure to select your correct size carefully. If you need replacement rings, we offer these as well. Also, since you're rebuilding your top end, you'll need the gaskets, which we offer. Keep in mind, if your cylinder needs machining, we offer complete machine work as well---check out our services.