Got them from army unit. Scare to get. Never used, not even mounted on a rifle.
Fits in AKSU-74's and AK-74's, with adapter could fit in any series, this muzzle allows to fire nose grenades Price: 85$ + 5$ Shipment via PayPal, first two persons who order will get for free original beryl manual.
Shipment takes 1-2 weeks until arrive.
more pictures: http://s1004.photobucket.com/albums/af162/SconDrago/Muzzle%20Brake/