OK, after waiting a few weeks on backorder, I just received my Jet 708119 Industrial-Duty Universal Mobile Base from my favorite online store, Amazon. "Industrial"? With all due respect to Jet and some the other reviewers here, you've got to be kidding me! (I deducted one star for every $10 by which this unit is overpriced, but ran out of stars.) Word: By spending a few hundred bucks on a small metal press, drill press, MIG welder, some raw steel, and a couple gross of the kind of cheap, "lockable" (not!) plastic casters included with this unit, you could rapidly manufacture these things in your garage for $15 a pop, max. Yeah, I know, I know. Why, this unit reliably holds 1200 lbs! [Highly doubtful. But even if the cheap plastic of which these casters are made can handle that kind of load, normal motion over a concrete floor will wear them down to nubbins in no time flat.] This unit is stable! [No way - I can turn every one of the "locked" casters with my thumb, indicating that they will do almost nothing to resist any lateral force of an order sufficient to overcome the inertia of any tool weighing much over 100 lbs.] This unit is a whole lot better than other comparable units! [If so, then other mobile bases are even more of a joke than this one.] Good grief, Jet. If you're going to manufacture an "industrial" mobile base and then charge the end user up to ten times the cost for which he could make the thing himself (with the abovementioned tools), at least use steel casters! Yeah, yeah, I know - what about those poor souls with wooden instead of concrete floors? [Clue: People with wooden floors shouldn't be rolling 1200 lb. tools around on them. And in any case, why not let everybody know the casters are plastic, so that those who have real concrete shop floors can try something else?] But steel casters don't lock as well as plastic or rubber! [Clue: Maybe not using friction alone, like these cheap/nonfunctional casters vainly attempt to do. But steel casters could easily be manufactured or modified with a locking gear, a spring-loaded pin through a hole in the wheel, or some other positive locking mechanism, no problem.] If one didn't have to worry about matching the ridiculous corporate advertising budgets dedicated to hyping this kind of function-challenged product, one could double his money selling superior units for about $25 or $30 each. Argue all you like, but that's a fact. I don't know about anyone else, but resist as I might, I get offended when my intelligence is insulted by people trying to pass off mere plastic, space-age or otherwise, as a heavy duty, abrasion-resistant load-bearing material suitable for this kind of application, especially in unmotorized, easy-to-manufacture Taiwanese products that have almost no moving parts and a price tag approaching $100...particularly when the casters don't even lock as advertised. Caveat emptor. The fit and finish are nice enough, but in this kind of product, functionality is all that counts.