This adapter will replace your 5/8-24 Direct thread barrel adapter and will allow you to use any 1-3/8×24 MALE, Quick Detach system out there on the market. This adapter also gives you roughly an added cubic inch of volume, adding to the sound reduction. There is plenty of room for any of the muzzle devices as well. (i.e. Muzzle Brakes, Flash Hiders, etc.)