Looks the same as Phoenix Racing:
https://mad-us.com/mad-bmw-s55-m3-m4...ow-air-intake/
15hp = ~2whp depending on drivetrain loss
Simply removing the factory charcoal filters can net similar gains, so the HP claim isn't unreasonable. Upgraded turbos are able to benefit more from aftermarket cone intakes.
One thing to consider is the limited clamping area between the MAS housing and filter flange with the short (Bank 2) intake pipe. A slightly extended pipe would be more ideal for filter fitment.