For use with the Arrow T72 staple gun. The exclusive design of the gun, along with the insulated staples, allows the safe and secure installation of all types of wiring up to 15mm / 9/16in. Options available: Clear Insulated Steel in sizes 5 x 12mm and 9 x 15mm.Clear Insulated Hardwood in size 5 x 12mm, designed specifically for use in harder woods.