1999-2004 Honda 400EX TRX400EX Red O-Ring Chain & Silver Sprocket 15/38 94L 15 Tooth Front Sprocket, 38 Tooth Rear Sprocket and 520-94L Red O-Ring Chain All Race-Driven sprockets meet or exceed OEM specifications and use hardened S45C steel. O-Ring Chain helps keep the pins lubricated which reduces friction and helps the chain last longer. Fits 1999 2000 2001 2002 2003 2004 Honda TRX400EX 400EX