PISTON KIT NAMURA Z50R 78-99 XR50 XR50F 00-03 CRF50 04-17 1MM OVERSIZEPiston Kit Namura Z50R 78 99 XR50 XR50F 00 03 CRF50 04 17 1mm Oversize Features: Machined smooth piston crown to reflect combustion heat while reducing carbon buildup Hard anodized piston crown with a hardness of HRB 105 MOS2 coating to draw heat through piston walls and out the bottom Minimized piston expansion and contraction Pistons are more resistant to wear and scuffing, expand less with heat and are stronger Higher Performance piston without a