I've seen photos of that mic for a couple years or so.
It's more like a Schoeps DMS setup than a tetrahedral ambisonic mic. Think full horizontal plane Mid Side with independant control over mic patern and angle. Once converted to B-format, standard ambisonic decoding would work for the horizontal plane. The key is in converting the 4 raw mic feeds to B-format.
Oops, scratch that. I posted before looking at it.
Just checked the listing and this is not the mic I was thinking of, I'd forgoten about this adaptation. This one is tetrahedral and would operate as a full sphere ambisonic mic including height information. The one I was thinking of uses the same capsules but the four are arranged like a cross in the same plane, facing the four cardinal directions.
This one would also need the raw microphone feeds (called A-format, unusable in that format) converted to either 4-channel B-format (the universal ambisonic format) or directly to virtual microphone outputs (single mic, stereo pair, or any number of coincident 1st order mic patterns) via software. There are freeware VSTs and comand line softwares that can do that, but better implementations do sophistcated things like attempting to correct for the distance between capsules and equalizing the response for each based on response measurements. To use this correctly requires a disposition to do a lot of research and geek tweaking to get the requied software together and even more to compensate for the capsules not being as coincident as the better known ambisonic mics. So unless this comes with software that does that, you'd need to have access to measuring equipment and be prepared to spend a good bit time and effort turning yourself into a tetrahedral mic expert in order to get this to work well.
And as Rich observed, the capsule spacing seems large, which agravates the compensation issues. But, if the price is right, it could be an interesting project for a mic experimenter.