Stern Defense SD HBC9 Muzzle Device Black 003-SD HBC9-D1-M. Machined from 6061 aircraft grade aluminum billet and hardcoat anodized. 3.25 inches long and 1.3 inches across the widest point. Note: Comes with crush washer. Specifications for Stern Defense SD HBC9 Muzzle Device: Manufacturer: Stern Defense Gun Model: AR-15 Additional Features: Threaded .5-36 Condition: New Color: Black Fabric/Material: Hard-coat Anodized Features of Stern Defense SD HBC9 Muzzle Device 6061 aircraft grade aluminum. Hard-coat anodized. Sturdy construction. Light weight construction. 9mm Threaded .5-36 Package Contents: Stern Defense SD HBC9 Muzzle Device What firearm models does the manufacturer say Stern Defense SD HBC9 Muzzle Device is compatible with? The manufacturer suggests that Stern Defense SD HBC9 Muzzle Device is compatible with AR-15Stern Defense 003-SD HBC9-D1-M: SD HBC9 Muzzle Device Black 003-SD HBC9-D1-M Black