A ratcheting single knob secures this block to any of our NATO rails to create quick release handles, EVF mounts, monitor mount and more. The quick release block has two tapped 1/4-20 and two 10-32 tapped holes on the top to allow the addition of our handle mounts, 60 mm rail blocks or our 1/2-13 flange mount to allow you create a wide range of quick release mounts.