1/2 - 28 to 15mm x 1mm thread adapter
(1/2" wrench flat for standard M16 armorer's wrench. Machined from 4140 chrome-moly steel. Black Oxide or Parkerized finishes available)
This part adapts the AR standard barrel thread and other 1/2 - 28 threads to take a G3 flash-hider and other G3 muzzle accessories.