The Doughty Clamp combines strength and durability. Constructed from high-tensile aluminium extrusion supplied as either polished aluminium or with a satin black powder coated finish [available to order if not listed]. They fit pipes with outside diameters between 48 and 51 mm. The Standard clamp will take an M12 nut or bolt head, allowing the user to create their own fixings. The lightweight clamps come with a Hex Nut instead of a Wing Nut as shown. Takes M12 bolts.