Not required for use with Kreg cabinet mount but worked for some of my drawers. It takes a few extra seconds to use, but ensures the jig doesn't move when drilling holes for screws. I wish it could be adjusted by simply squeezing rather than turning the screw like standard vise pliers as my drawers varied in thickness and I often had to fiddle with the adjustment screw between uses (requires two hands and therefore forced me to turn the screw release correctly aligned clamp). It's pretty overloaded for its intended use. Very heavy considering the bracket that's supposed to hold it is just plastic.