Renthal Aluminum Rear Sprocket 38 tooth fits the following Hondas: 1986 ATC250R; 1986-1992 TRX250R Four Trax; 1993-2010 300EX; 1999-2010 400EX; 2004-2010 TRX450R; 2006-2010 TRX450ER. $25.00 plus $4.90 shipping.