Pick a different one - DoubleStar Adjustable .750in Low Profile Gas Block

This product is poorly designed. The adjustment screw (the black one, by the way- there are no instructions at all with this) faces the receiver rather than the muzzle, so the hand guard probably has to come off to adjust it. The other thing- for my low mass operating system build, the adjustment screw ended up so deep that the brass set screw actually threads across the end of the adjustment screw... ridiculous.