The Madera C4 Drive Side Guard is made from injection molded plastic. Must be used with the proprietary steel insert which threads on 14mm axle & substitutes existing drive side jam nut. Can be used on all 14mm Rear Madera & Profile Cassette Hubs (including Madera V-2 & Gulf Coaster, & Profile Mini, Totem, Elite, & Zcoaster). Can be used on either RHD or LHD Hubs.