This is a LanTac USA LLC Muzzle Brake known as the Drakon chambered in 7.62X39, model DGNAK47B.
LANTAC Dragon(R) Muzzle Brake DGNAK47B(TM) for AK47 Rifles & Variants. Manufactured to the highest quality standards and featuring a patent pending design" the LANTAC DGNAK47B(TM) Muzzle Brake offers improved recoil management and muzzle rise over competitors' products. Its unique Short Energy Pulse system reduces length of recoil so that repeating shot energy cannot overlap and knock the shooter off target. Full auto fire is possible with massively reduced recoil and muzzle climb" meaning that all shots fall on target.
Features:
14X1MM Thread pitch
Serial numbered for quality control
Comes with crush washer
Hardened Milspec steel construction