NATO Lock Magic Arm 7 is an articulating arm with NATO standard quick release and clamp on each end, ratcheting center thumbscrew with rosette, and stainless steel ball joint construction. The rail portion can bolt into a 1 4 20 or 3 8 16 hole using the included screws. Set screw can also be installed to prevent twisting. The rail is also threaded for 1 4 20 and 3 8 16 so accessories can screw into it. The clamp portion of the kit can also bolt into a 1 4 20 or 3 8 16 hole using the included screws and it is also threaded for 1 4 20 and 3 8 16 so accessories can screw into. Great for attaching LCDs, lights, audio recorders and much more Compatible with RED Swat Rails, Zacuto Z Rails, and many 3rd party NATO products.