Just make sure its not a Chinese ripoff of the bauer or something crazy like that.
I have a Drager DE-100 which is a Bauer under the Drager banner I believe. All the data I see on the accompanying books shows it to be a Bauer Junior II. It takes the P21 cartridge but only has microsieve and activated carbon filter as its electric. Interestingly mine has Drager stickers on it but then the compliance plate shows it as a Bauer along with the manuals. One and the same I think. In any regard its well built and looks like a German compressor, in contrast with the crap Chinese copy of the Coultri I bought first.
If the one you talk about has a triplex filter the filter is for a petrol model? Is the one you are looking at, a petrol model or electric? Is the label saying "not breathing air", on the filter tower or the filter canister inside? If on the tower, perhaps it was sold originally with the tower but no canister inside, thus the duty being paint ball with a condensate tower only. Maybe sold this way to meet the paint ball market without tooling for a different compressor, but sold cheaper as a paint ball compressor only. In other words making the compressor fit all requirements by the removal of the filter canister and adding a label and then sold cheaper. If so it might be a good way to get a quality breathing air compressor at a cheaper price, then just slip in a breathing canister if it will fit in the tower, and hasn't been modified to stop a cartridge being fitted.
I double filter mine with the P21 standard filter on the compressor and then via a personal filter a 0520 replacement cartridge (that suits a number of personal filters as well as the Coltri MCH-6 compressor.)