We figured it's a "C". We used to say B+ or super B but it is now usually listed as a C. All those other rigs built on the E350 and E450 chassis are usually designated C.To confuse the issue, I'm pretty sure the new Phoenix TRX would be considered a B.Side story: We were just at the factory getting our 12 volt system fixed (more on that elsewhere). I briefly met a man that owns a 2100. He was picking up parts and got to check out the TRX. It was love at first sight. It is almost identical to the 2100 inside but sleek on the outside and perfect for stealth camping. It can slide into most regular parking spaces without a problem. It can only tow 3000 pounds but that works for what this gentleman called himself - a "roadtripper". He was seriously excited and I suspect he'll have a new Phoenix TRX soon. (Hi M!)2100 and 2350 owners BEWARE - your perfect rig might be waiting for you at the factory or a Camper's Inn lot. Visits to just "check them out" could result in a sleek new rig.