Strike Industries AR Enhanced Castle Nut & Extended QD End Plate, Black The Strike Industries AR Enhanced Castle Nut and Extended End Plate stands out aesthetically and functionally. The steel castle nut has been lengthened to match the extended end plate which supports more of the receiver extension's threaded area. It features an ambidextrous Quick Detach sling swivel mount that allows for weapon manipulations in tight spaces and under stress without the risk of pain from a pinched hand from using a sling attachment. Note: First position will be lost. The recommended torque value is 40 inch/lbs.