Our 4140 gun-quality 'Stress Free' steel gas blocks feature: 

• Nitride (QPQ) finish

• Fits any .750" diameter barrel

• Dual steel set screws ensure tight fitment (screws included)

• Screw hole distance measures @ .440" center to center

• Honed interior surfaces make installation of barrel and gas tube stress free

• Low-profile allows it to fit under any rail system

• Does not include a steel gas tube roll pin