The Uni Air Filter is two layers of foam that will trap small and large particles like dust and dirt helping prevent anything reaching to the cylinder. Uni Air Filter is produced of high performance foam and biodegradable. The Uni Air Filter has a seamless design that allows for a maximum amount of air flow to your machine. The Uni Air Filter is easy to clean with the Uni Air Filter Cleaning Kit and will help cut the grease and oils down so you are able to reuse indefinitely.Also Fits:Yamaha BEAR TRACKER 1999-2004Yamaha BIG BEAR 250 2007-2009Yamaha BIG BEAR 2x4 400 2000-2004Yamaha BIG BEAR 400 IRS 4x4 2007-2012Yamaha BIG BEAR 4X4 400 2000-2006