Slip-on design utilizing an integral spark arrestor and high quality packing material Forestry approved and under 96 decibel legal Combination of stainless steel (mid pipe area), anodized lightweight aluminum (canister) and super lightweight titanium (end cap) providing performance, durability and weight loss over stock mufflers and the competitors This product can be used with Yamaha YZ400 98-02 Yamaha YZ426 98-02 Yamaha WR400 98-02