Blue O-Ring Chain & Silver Sprockets 12/40 92L 01-2005 Yamaha YFM660 660 Raptor 12 Tooth Front Sprocket, 40 Tooth Rear Sprocket and 520-92L Blue 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 2001 2002 2003 2004 2005 Yamaha YFM660 Raptor