The RetraxPRO bed covers have the same great benefits as the RetraxONE but are made with industrial strength aluminum, giving them the strength to support distributed loads of more than 500 pounds! The RetraxPRO features a limited lifetime warranty, meaning you'll never have to worry about your bed cover once you have it installed. Sealed ball-bearing rollers are mounted onto each section. This allows the retractable cover to open and close easily with one hand, without the need for pull straps, Velcro, snaps or springs. Ball-bearings provide smooth operation, preventing the cover from binding when opening or closing. The patented low-profile design is always flush, enhancing the integrity of your truck's style rather than overcoming it. Unlike soft covers that bulk up when rolled, the flush front cover streamlines the overall appearance and provides a firm, dependable seal that keeps out the elements and helps keep the bed dry. Your cover will seal tight and look good!