Piston ring kit 58mm fits for EX13 EX13D 4.5HP 4 stroke engine motor water pump ring pin clip assembly replacement This piston ring kit is designed for use with EX13 and EX13D 4.5HP 4-stroke engine motor water pumps.It includes a 58mm piston ring, wrist pin, clips, and related components needed for replacement.The set provides all necessary parts for rebuilding the piston assembly.It is intended as a direct fit replacement for worn or damaged rings and pins in compatible water pump engines. This component is not from the brand.References to models are used only to indicate fitment.