Cambro Camshelving Vented Shelf Kit, 21 x 72 inch -- 1 each.For use in kitchens, freezers, coolers, pantries or dry storage. Best for storing perishable products that benefit from air flow around them. Each kit includes 2 traverses and several vented shelf plates to build a single shelf. Made of smooth polypropylene. Wipes clean. Rust proof. Traverses each have a steel core and are designed to bear weight, like the posts.