I have an Extang Classic Platinum on mine with no problems. It uses a snap style that is fully adjustable for cold or warm weather. The snaps rotate in to two positions and the ribs adjust as well... It hasnt leaked either...not saying its water proof just havent seen water in the bed yet

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Truxedo low profile. Absolutely love it and would not get anything else. Completely watertight. I haven't had an issue with it in the cold and it has seen some cold and a lot of snow in the colorado mountains.

http://www.truxedo.com/lopro/land.php

 

I have the soft tonneau with the two support bars across the bed. Bought the tailgate seal and used duct tape on a few other spots and it's now dustproof. However, it flops like crazy at highway speeds. I'm looking to buy one of them tri-folds that looks like a heavy canvas type material.