FLASH HIDER Original Bulgarian KRINKOV style 4-Piece Flash Hider. 24x1.5mm right-hand threading, chrome-lined. Works with 7.62x39, 5.45x39, and 5.56x45 calibers. Also, works perfectly with Krinkov style, full length, and compact length (CR Type) rifles! This is the ORIGINAL design of the 4-piece flash hider! There have been several attempts to duplicate this item, but copies fail to compare with the looks and functionality of this original.