The O2 RUSH High-Performance air filter is the ultimate performance upgrade for modern CRF250R, CRF250RX, CRF450R and CRF450RX models. Designed with a coarse outer foam layer and fine inner layer, it flows dramatically more clean air than the stock filter – giving you sharper throttle response, more top-end power, and better engine protection in dusty conditions. The durable rubber sealing rim and aluminum-reinforced mesh create a perfect airtight seal every time you close the airbox. Easy to maintain: just clean with O2 RUSH cleaner, let dry, re-oil, and reinstall. One filter lasts the lifetime of your bike with proper care. Perfect for motocross, enduro, desert racing, or trail riding.