Insulated Metal Staples secure a large variety of cable types including: NM, BX, MC, AC and UF cables. These staples offer a durable polyethylene insulating sheath to prevent arc faults if the staple is over-driven through a cable jacket. Strong steel constructed staples offer sharp, burr free tips which easily bite into wood upon hammering and deter wood from splitting. Do not drive the staple beyond the insulation stops to achieve a clean insertion and secure wiring without damage to cable or wood. 1/2 inch staples secure 2 conductor #12 and #14 Non-Metallic BX, MC, AC and UF cable.