The Madbull Officially Licensed Noveske Low Profile Gas Block with Switch Block is not made to fit inside rail interface systems. The front of the gas block is to remain accessible so the user can adjust the amount of pressure that's routed backwards to cycle the bolt. Obviously this feature is only made to imitate the real product and serves no function for airsoft but it is a unique feature that displays Madbull's attention to detail in making an accurate replica.
Note: This product is for airsoft use only