This is a complete OEM Quality Piston Kit – standard size for the Z50R 88-99 and all XR50/CRF50 models. Comes with the wrist pin, rings, and circlips.  Honda charges about $44.00 for the same parts which makes our kit an easy choice.  We also recommend getting the top end gasket kit (part # TBW1174) or complete gasket kit (part # TBW0717) with this piston kit.