The Tac 9 Low Profile SPR Gas Block is meant to exchange your triangle front sight post or your current gas block. Using this gas block add for a way more realistic look to your rifle by mimicking the particular gas block and tube style used with free float rails on real AR15s. The low profile design makes this gas block sufficiently small to suit inside most aftermarket rail system, and therefore the lightweight aluminum construction makes it extremely durable. This Gas Block may be a good way to form your gun look more realistic.