The dimensions of the box are 21" wide, 48" long, 48" high. It’s surprisingly stable as a result of the weight of the stainless steel frame, axel, and heavy duty Schwable wheels.
It does, however, have some wind drag. A gusting head wind or cross wind affects the “feel” and momentum but not the stability. I might chop 6 inches off of the bottom to lower it a bit. We’ll see.
I’m in the process of coming up with version 2.0 designs and material sourcing. I would like a shelving unit as well as the ability to put entire lengths of wfp inside of the actual box. Stay tuned.