Use extra collars to allow the use of one BMD� across multiple firearms. - A2 Adapter Collars work ONLY with the following non pinned & welded LANTAC Dragon� Muzzle Brakes: - DGN556B (5.56/223) - DGN9MMB (9mm 1/2x36) - DGN9MMC (9mm MPX) - DGN9MMD (9mm...