Our hump rack covers are made of reinforced bright red PVC material that allow them to be water and mildew resistant. The covers are fastened with velcro for quick release. Specifications: Red in color PVC material Various sizes Download Spec SheetTabsPart Table Part Number Size Notes HUMPCOVER1 16" x 25½" x 6" Fits #HUMPRACKHR-1 and #HUMPRACKHR-2 HUMPCOVER3 24" x 29½" x 6" Fits #HUMPRACKHR-3 and #HUMPRACKHR-4 HUMPCOVER5 33½" x 35½" x 6" Fits #HUMPRACKHR-5