2012 Ram 1500 has plastic around the box top and tailgate top and nothing on the front box edge so the gap between the front edge of the cover and box is too big for the included seal to fill. Added another piece of the same material that I found at local hardware store. The Roll-X is the best full bed access/hard cover that I could find. Easy to install, great fit, love the low profile look. Only negative I could find was cover has to be unlatched to allow tailgate to slide under the rear seal when closing tailgate. Installation took longer than it should have because I had to find seal for front gap on the Ram.