Easily mount your bicycles on the CC-125 Cargo Box Bike Rack Adapter, accommodating tire widths up to 2 inches. No hassle, secure transport for your next adventure The racks are made of sturdy steel material with black coated finish, will not get rusty With (4) Tire Holders, (8) Carriage Bolts, (8)Spacers, (8) Lock Nuts, and (2) Tie Down Straps included in the package, you'll have everything you need to ensure a safe and secure bicycle transport system