So they must clamp around the metal part of the fender and the cam lock keeps them on with compression? Any issue if your truck has fender flares?

 

The outside has a lip that is molded to hook or grab the stock fender or flare, the no drill hardware is an allen bolt going through a stainless tab that rotates between the fender liner and inner fender lip to squeeze the flap to the fender. I thought I might lose one this winter by backing into deep frozen snow etc but they are doing just fine. I used Husky liners before these. I painted my holes that I drilled with the Husky. The Weather techs installed a LOT faster.