Blue Non O-Ring 102L Chain & Silver Sprocket 15/38 for 2004-08 Yamaha 350 Raptor 15 Tooth Front Sprocket, 38 Tooth Rear Sprocket and 520-102L Blue Non-O-Ring Chain All Race-Driven sprockets meet or exceed OEM specifications and use hardened S45C steel. Non-O-Ring chain doesn't have o-rings between the links so it is lighter, thinner and has less drag. Fits 2004 2005 2006 2007 2008 Yamaha YFM350 Raptor