Hardened Carbon Steel Construction 3-Thread Adaptor. Anti-Rust Black Oxide Matte Finish. Fits standard Ruger 10/22® barrels. 3 thread dimensions in one fitting: 3/4 NPT \ 13/16-16 \ 3/4-16UNF.  Accepts JÄGER Re-Direct Flash Hiders,  JÄGER PMC 10/22 Barrel Shroud, JÄGER "Versa-Brake" System, Gestalt Verdampfen Compensator and Ferragane Mini. Connects to barrel with nylon-tipped stainless steel set screws. No machining required to attach this part.