JMac Customs 4C 14-1LH Slim 4-Port Muzzle Brake Black Nitride Black. This one of a kind combination device gives you control over your firearm like you've never had before while only adding 1.5'' in length and 3 oz in weight The RRD-4C has cut-outs on the top sides to allow gas to vent upwards in turn forcing the barrel downwards and virtually eliminating muzzle rise with an extremely low flash signatureReduces flash on barrels 11'' and longer See how the RRD-4C compares to 28 other popular AK muzzle devices in Flash Reduction Specifications for JMac Customs 4C 14-1LH Slim 4-Port Muzzle Brake: Manufacturer: JMac Customs Color: Black Finish: Nitride Fabric/Material: 17-4PH Stainless Steel Threads per Inch: 14x1 LH Gun Make: Kalashnikov Length: 2.1 in Weight: 1.8 oz Condition: New Features of JMac Customs 4C 14-1LH Slim 4-Port Muzzle Brake 4 Port Muzzle Brake Package Contents: JMac Customs 4C 14-1LH Slim 4-Port Muzzle Brake JMac Customs RRD-4C-14-S: 4C 14-1LH Slim 4-Port Muzzle Brake Black Nitride Black