Dunno if anyone else here at NPN owns one of these tanks for use with really heavy gear, but we do. Trouble is, the plastic knob on main control is pretty fragile and subject to breaks from crashes in field use.
After doing an epoxy job on yet another, I just learned that B&H can source them for $25. Can’t say how long that might last, so if you own a Studioball, it would be a pretty good idea to order one and toss it in a drawer. Next time you drop your tripod or drop something on it, you could well need a replacement. Or and epoxy session.