Rearden MFG Cyka Flash Hider 26-1.5 LH Black. The Cyka uses a 25mm wrench. The Atlas has 1 1/16wrench flats on the rear; we recommend using a crows foot wrench. The Cyka muzzle devices are designed to face mount on 24 and 26mm threads helping to solve many common AK alignment issues. Specifications for Rearden MFG Cyka Flash Hider: Manufacturer: Rearden MFG Color: Black Features of Rearden MFG Cyka Muzzle Device Atlas and Atlas XL Compatible Plan B Compatible Package Contents: Rearden MFG Cyka Muzzle Device Rearden MFG 10243: Cyka Flash Hider 26-1.5 LH Black