This innovative low profile gas block not only weighs less than 2.0 Ounces, but clamps tightly to .750 diameter barrels. The Daniel Defense low profile gas block fits perfectly under all Daniel Defense rails. The Daniel Defense AR-15/M4 Low Profile Gas Block is constructed from 4150 hardened steel and Military Specification Heavy Phosphate Coating. Details * Solid Steel Construction. * Military Specification Heavy Phosphate Coating . * Precision CNC Machined. * Fits under all Daniel Defense rails. * Clamps to barrel.