This odd thread adapter allows you to thread an AR15 or other 1/2x28 threaded muzzle brake to your Yugo M92 massive thread of M26x1.5 LH. Machined steel with locking notches for detent and finished in Black Oxide. **(Muzzle brake to be used have a large enough inner diameter for the caliber) **NOT FOR USE WITH 7.62X39 CAL-.223/5.56 Inner Diameter is .335