This is a Fortis Manufacturing, Inc. Gas Block known as the Low Profile Steel, model F-LPGB-SS.
The Fortis low profile gas block is designed to work in conjunction with today's match grade barrels. It is designed for .750 gas seats and attaches to the barrel with two set screws. The gas block comes with a roll pin as well as two set screws.
Features:
Two set screws
Made in America
Low Profile