Ah, that explains a lot. I remember seeing many vehicles kitted out like this on the lakes during ice fishing season when I was a kid. Lodges would usually trick out a few vans with these to take guests out to the ice houses.
The guy who designed them did so after his eleven-year-old son, Matt, drew a picture of a truck with mini tank treads where the wheels should be. Luckily, dad was an engineer and when he looked at the drawing thought it might be possible to actually make the things in real life.