This starter clutch assembly is compatible with TTR125, TTR125E, TT-R125, and TTR125R models manufactured from 2003 to 2007.It corresponds to OEM part numbers 4TU-15590-00-00 and 5AP-15517-02-00 and includes a gear with reference code 5HH-E5517-00.The assembly is constructed from metal and designed for low noise , quick starting, smooth engagement, impact resistance, and load-bearing capacity.engineering ensures consistent performance.