Listen, there's no reason for you to worry about whether or not your gas block will fit under that slim handguard of yours. Just get the Troy Low Profile Gas Block and create the sleek AR you've been dreaming of. What's more, the Troy Low Profile Gas Block is also designed to cover the area used by traditional A2 front-sight gas blocks, so if you're upgrading your rifle, you can cover up those ugly taper-pin holes with this block. The 2-inch unit is machined from 4140 steel and treated with a durable manganese-phosphate finish. The inside diameter of the Troy Low Profile Gas Block is .750 inch, and you'll have to find your own gas-tube roll pin to complete the project.