The best filter in the world can't do its job if there are leaks in the seal of the airbox. That's why Twin Air provides a complete line of products to ensure a leak-proof, fool-proof fit. Twin Air's Power Flow kit comes with a rigid, lightweight, billet aluminium cage that provides a tight seal to the airbox and replaces your flimsy plastic stock cage. Includes a Fire-resistant Twin Air Filter. YAMAHA YZ125 97-25 YZ250 97-25 YZ125X 20-25 YZ250X 16-25 YZ250F 01-13 YZ400F 98-99 YZ426F 00-02 YZ450F 03-09 WR250F 01-02 WR400F 98-99 WR426F 00-02