5/8 X 24 INTERNAL THREAD (MOST AR10, .308/7.62, 300BLK) 3/4 NPT OUTER MOST THREADS (FITS WIX 33528, 33115, 33974, 33640, NAPA 4003, WIX 24003) MUZZLE BREAK RE-ATTACHES FOR EASE OF USE SOLVENT CATCH FITS OVER THE BIRD CAGE FLASH HIDER THREAD PROTECTOR INCLUDED