The Armeg 11mm x 76mm Twister Square Nut Driver is for fastening sheet metal screws and square nuts bolts, etc. Suitable for most 11mm square nuts, it is also perfect as an accessory to the Twister Impact Roofing Bolt Drivers whilst being suitable to work with impact drivers. Instead of swapping machines, from your impact driver to your drill and back again, the Armeg Twister series lets you keep using the impact driver to product the same results. Made from a high quality alloy for durability and strength in high torque applications, the UK made nut driver includes a bored area to accommodate extruding bolt threads.