I have read that the PT2 base (which is the same size as an Aerotank base) will "fit" on a PT Mini, but "looks funny", as should be expected because the outer rim of the base is much greater in diameter than the Mini's base. This implies that the inner hole's diameter on both is the same, as it would leak if the o-ring around the lip of the hole did not match up to the Mini tank's bottom opening. My only Aerotank base is on my PT2 right now, and I just refilled or I would try it out, but I would rather recommend that you just pick up a PT2 and an Airflow Control Valve aka Aerotank base together and try it out. I was a diehard PT Mini fan myself until I tried the Aerotank base on a 2.5 ml PT2, on 01/21/14, and I haven't used anything else since!