This gas block replaces your existing front sight to provide a simple, low profile design that can be used to mount a rifle length forearm to a carbine length barrel.Specs:Compatibility: 0.750" BarrelsMaterial: 4140 Chromoly SteelFinish: Mag phosphateWeight: 1.8 oz.Width: 0.90"Height: 1.48"Proudly Manufactured in the U.S. using U.S. sourced materialIncludes: (1) gas block with (2) screws - Torque Spec: 30 in-lbNote: Gas tube roll pin is not included. Roll pin included with all of our gas tubes.