When you need the cargo capacity that a rack provides, but won't get in your way when the going gets rowdy Full Challenge Sailcloth 200 denier UHMWPE / Polyester woven laminated fabric Super tough rattle free mounting with metal hardware Fiberglass internal and exterior stiffeners High density closed cell foam frame sheet Please note: these panniers are made with a minimum of seams but are not fully waterproof Made in the USA with domestic and imported materials