I don't think i've seen this port mentioned yet, but it's another 3rd party option (for the Panasonic 8mm FE and presumably the Olympus 12mm):
I can't comment further on this as i have not seen it, let alone used it. From the photos, it looks very much like the 4.33" Nauticam acrylic dome.
I recently had this port show up at my door. I haven't had a chance to use it yet, but it looks pretty nice!
I have never seen a formal review on this port, but I do know that Alex Mustard had borrowed one from someone earlier this year and posted some nice pics using it on his facebook. He said it worked well for him, and that was good enough for me to take the leap and buy one sight unseen. It is the same dimensions as the nauticam port, except it is optical glass instead of acrylic. They even make replacement glass that goes in the nauticam port. Thought this was worth mentioning about this port since someone was asking about the 8mm FE