I have the Revolver X4. Since I have a CarbonPro bed, I thought finding a cover was going to be impossible with the GM ones being the only option. Anyway, got some custom clamps made and fit was perfect as it can get (i'm a little on the OCD side). Install was easy and use and functionallity is perfect for me. Product and overall cost was a little on the high side but I definetly do not regret it....I often try to remember that you usually get what you pay for because I am rather cheap and in the past I wound up buying things twice cuz I wanted to save...LOL. As far as water tightness, I haven't had any experience yet because I doesn't rain much in my part of the Island but I am hoping there wont be any issues. After installation, I checked from the inside and saw no gaps (no light showing through) so I am assuming its as tight as it can be.