This item is a pain to use. While the videos online show it as quick and easy, it requires three hands and a screwdriver to attach to the knife. Once the equipment is attached, the alignment guides are worthless. I used a standard sized whetstone, (7''x3''x2'' LxWxD), and the guide did not allow for the right percentage. Even at the lowest setting, it didn't get a low enough angle for the blade and the guide itself got in the way of providing a nice smooth slide across the stone. Maybe if the stone was higher up off the ground it would have worked better.I am not impressed with the guide thus far, but will work with it some more. Might work better with DMT's stones.