Standard Bore Piston Rings Kits Motorcycle Fit for CM250C 250 Twinstar 200 185 XL100S XR100 XR100R 13011 KB4 305 Piston ring set designed for use with standard bore motorcycle engines.This kit includes all necessary piston rings for proper engine compression and performance.Compatible with models requiring part number 13011 KB4 305.The rings are engineered to fit precisely in the cylinder to effective sealing between the piston and cylinder wall.Intended for motorcycles with specific engine configurations including CM250C, 250 Twinstar, 200, 185, XL100S, XR100, and XR100R.This replacement part supports engine efficiency by maintaining oil control and blow-by during. Compatibility Statement: This is not an manufacturer part.Brand/model references are used for fitment guidance.