NO TOIL manufactures the world's best 2-stage foam air filters. Using only the best flame-laminated dual-layer foam bonded with the highest quality glue they hand make each foam filter to stand up to the roughest and toughest riding or terrain. NO TOIL filters can be used with NO TOIL biodegradable clean in water cleaner providing the best air filtration system in the world. Fits: Yamaha YFB250 TIMBERWOLF 2WD 1992-1998 YFB250FW TIMBERWOLF 4WD 1994-2000 YFM350ER MOTO 4 2WD 1990-1995 YFM350FW BIG BEAR 4WD 1987-1999 YFM350U BIG BEAR 2WD 1996-1999 YFM400 KODIAK 1993-1999 YFM400FWA KODIAK 4X4 1999