Retrax RetraxPRO MX - 14-18 Silverado/Sierra 5'9" - Wide Rail Model 80471Retrax RetraxPRO MX 14 18 Silverado Sierra 5'9" Wide Rail Model 80471 RetraxPRO MX bed covers are made with heavy duty aluminum slats covered in a matte powder coat, giving them the strength to support distributed loads of more than 500 pounds! The RetraxPRO MX 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