The Logan F400-1 fitting tool makes it easy to attach the back panel of a frame. Just select one of the 4 most popular types of inserts using the rotating insert holder. For best results, lock the frame between the body of the tool and the sliding head, then firmly squeeze the handle while keeping the body of the tool flat and straight on the framing material. The flat base of the tool makes it easy to adjust position and drive inserts into the frame. Once in place the inserts won't slide or bend and the backing will be stable.Works on wood frames (oak, walnut or maple) with a maximum width of approximately 7.5 cm.