Keldermann is the company, it's an ambulance setup.
We have semi-air on our front axle, basically big block leaf springs mostly to locate the axle and a pair of 7" double-convoluted air bellows to carry most of the weight. IIRC the bellows are rated at 3500lbs each, the weight they carry consists of the IDI engine, massive cow-catcher bumper, a 200lbs winch, and often a generator. Weight is enough to turn the leaf springs alone to negative arch like F250s have. But they are 1-ton leaves as the axle was still under the truck when we got it and had to be removed in field conditions. Bellows are mounted on top of the spring plates and right under the C-channels. Truck rides very well.
The rear is getting a pair of triple-convoluted bellows soon enough, again of the 7" size for its higher load capacity. 4-corner independent height control from the cab too. The none thing to watch out with the rear axle is if you make the pack too thin and you have low gears she will have a tendency to wrap under heavy throttle and load. Not a big deal, and there are easy fixes, just something to keep in mind.