I don't know about you, but when I'm off-roading I like to get as far away from civilization as possible. And what's the point of doing that if you're breathing in dirty air the whole time? That's where the OuYi air filter comes in. It's like a little angel on your shoulder, fending off dirt, dust, and debris from your Yamaha off-road vehicle. And let me tell you, this little angel knows how to party. Not only is it compatible with several Yamaha models from 1987-2000 (Kodiak 400, Timberwolf 250See full review