The lens adapter gives you a 52mm and 67mm threaded port on the front of your Kraken Smart Housing 2.0 and 2.0 PRO - KRH07 and KRH08. This will let you attach wet lenses like KRL-02, or anymacro lens.
It will accept any wet lens that you might have as long as you adapt to the 52mm or 67mm threads.