This carbon brush kit is designed for use in motorcycle starter motors compatible with 15-28HP engines.It fits models including 21163-7001, 21163-7010, AM133369, 41022015, and 41022005R, as well as additional compatible part numbers such as 21163-7022, 21163-7029, KAW211637001, KAW211637010, 21163-0711, 21163-0714, 21163-0727, 21163-0743, 21163-0749, 21163-7024, 21163-7034, 21163-7035, FR691V-AS04, SAB0172, 41021086, 593934, 693551, and LG693551.The brushes are engineered for single-cylinder starter motors and support consistent electrical conductivity.The kit includes all necessary components for direct replacement without requiring additional measurements.Its design accommodates various starter motor housings within the specified horsepower range.