These rail system tonneau covers protect your truck’s cargo area from the elements, improve gas mileage, and look great, too. They feature a no-drill installation and a padded aluminum frame that clamps to the bed rail with six insulated clamps, resulting in no metal-to-metal contact. Three pre-arched aluminum bows support the cover through heavy rain and snow, and the durable cast aluminum corner pieces are mounted with thumbscrews, for fast and easy removal of the front and rear rails. The adjustable snaps and framework guarantee simple cover attachment, and the black cover is made of durable reinforced vinyl with black snaps. The cover and crossmembers are easily removed for hauling large items.