The RetraxPRO XR is one of Retrax's premium aluminum series cover, combines industrial strength aluminum construction with an incredibly resilient matte finish. The RetraxPro XR optimizes cargo capacity with the cover open or closed, providing the ultimate versatility in cargo management. The Trax Rail System will work with most T-slot accessories from Yakima, Thule, Rhino Rack and many more offering endless possibilities. Pairing the Trax Rail System with accessories offers double the cargo capacity. This unique technology frees up the hitch with the ability to mount bikes, coolers, outdoor gear and more on top of the bed cover by combining the Trax Rail System with the t-slot accessories. If you have any questions about RetraxPro XR tonneau covers give us a call at 800-272-5362.