The AR-15 low profile gas block sits over the barrel’s gas port and routes gas back into the action without the bulk of a fixed front sight base. It sits flush under free float handguards and keeps the rifle lightweight and clean. Builders install it on barrels with a compatible gas port diameter and secure it with set screws or a clamp. It works with carbine, mid-length, and rifle-length gas systems. Shooters use it on free float builds that require a handguard to extend past the front sight position.