Open Box Dealer Demo Stern Defense SD FH9 MOD1 Muzzle Device Black. Manufactured to the highest quality standards right here in the U.S.A. Full auto tested to ensure reliability and function under sustained fire. The helical right handed 1:6 twist design keeps the flash hider tight under even the most strenuous situations and ensures powder burn eliminating flash signature. Machined from US Mil-spec AISI 4140 steel and black nitride coated to provide a lifetime of abuse. . Notes: Comes with crush washer. Specifications for Stern Defense FH9 MOD1 Muzzle Device: Manufacturer: Stern Defense Color: Black Finish: Black Nitride Gun Model: AR-15 Additional Features: Threaded .5-36 Features of Stern Defense FH9 MOD1 Muzzle Device Full auto tested US Mil-spec AISI 4140 steel. Sturdy construction. Black nitride coating 9MM Threaded .5-36 Eliminates flash signature. Right handed 1:6 twist helical flutes Weight: .21 lbs Package Contents: Stern Defense FH9 MOD1 Muzzle Device What firearm models does the manufacturer say Stern Defense FH9 MOD1 Muzzle Device is compatible with? The manufacturer says that Stern Defense FH9 MOD1 Muzzle Device is compatible with AR-15Stern Defense 03-SD FH9-MOD1-M: SD FH9 MOD1 Muzzle Device Black 03-SD FH9-MOD1-M Black