An F-clamp with a specially designed head that fits into the slot of power tool guide rails. It is compatible with the following guide rails, amongst others: Festool FS, Makita, Milwaukee, DeWalt, Kreg, Rigid, Lidl Parkside and Aldi Workzone (unfortunately not Bosch). The clamp has a plastic pad on the swivel shoe to protect the work surface. Please check the clamp slot in your guide rail prior to ordering. The spigot is 11 mm wide by 7.5 mm thick and 60 mm long. 160mm capacity. A removable plastic stop on the end of the clamp allows the arm to be removed, turned around, and repositioned. This means the clamp can also be used as a spreader.