Effective muzzle brake with integrated HexaLug interface. Compatible with all 7.62 mm suppressors featuring our HexaLug quick attach mounting system. Due to the one-way compatibility of HexaLug it is impossible to install a suppressor of a smaller caliber. This eliminates the risk of a 5.56 mm suppressor being installed on a 7.62 mm muzzle brake. On rifles that are primarily or exclusively used with a suppressor, a muzzle brake should be used instead of a flash hider. The ports of the muzzle brake redirect high-pressure gas towards the side and therefore prolong the life of the suppressor. Please note the increased intensity of the muzzle blast affecting bystanders next to the shooter if the rifle is used without a suppressor. Thread Size Guide: 5/8″ – 24 UNEF Standard thread size on almost all American made rifles chambered in a 7.62 mm caliber. M14 x 1 Fits all variants of the Czech made vz.58, occasionally found on hunting rifles. Does not fit AK47/AKM. M14 x 1L Fits all AK47/AKM variants except for newer ones with the M24 x 1.5 thread (AK-103, AK-104, etc.). M15 x 1 Fits Haenel CR300 and CR308 as well as many other rifles. Does not fit HK MR308 and HK roller-delayed guns (G3, etc.) M15 x 1 HK Specifically designed to cover the cylindrical section between the muzzle thread and the shoulder on an HK MR308. Do not use this with rifles made by Haenel. Other thread sizes may be introduced later on.