Hey Adrian
Yeah, when I originally ordered my skimmer, I wanted an external model with an airstar pump. Since the airstar med was still under development, Victor shipped me a med w/an eheim pump under the agreement that I would be shipped a retro fitted airstar to replace it as soon as they were ready. While it works VERY well, its not what I wanted. Since then the new pump was released; however, do the the RC configuration of the skimmer, the pump won't fit because it spins in the opposite direction as the eheim (which IIRC can spin both ways).
So the result was a pump that doesn't fit my skimmer
Being the great guy Victor over at ATB USA is, he agreed to take my skimmer back, and replace it with a new one. One built with the pump I want. But, instead of returning the skimmer, I found a buyer to make it easier on Victor, as cash in his hand is easier to pay the bills with that a used skimmer (and I could hook a local up with a killer deal).
So my new skimmer should be sometime this month. Hopefully around the week of the 11th
Here you can see why the pump doesn fit
On the internal models, it doesn't matter. But because the pump must be attached to skimmer body from the inlet and exhaust on ext models, it won't fit the current body.