This clamp fits into the slot of many extruded aluminium guide rails, including the following: Festool FS, Makita, Milwaukee, DeWalt, Kreg and Rigid. Check your guide rail prior to ordering. The spigot is 12mm wide by 7.4 mm thick and 60 mm long. The ratchet handle results in extremely fast set-up. Once tightened, the grip is rock solid and unaffected by the vibration from power tools. 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. Lifetime guarantee.