I bought this a few years ago from one of the Chinese "mega sites", Uxcell (http://uxcell.com/) for around $20 (they no longer have it). I knew it was a fake, since this particular model sells for £80-100 new, but was curious to see just how bad it looked. There's a good document from Mitutoyo which details the differences in several imitation products: http://www.mitutoyo.com.sg/documents/Imitation%20leaflet%206pp.pdf. My indicator is model 513-404.
The quality is, as you might expect, pretty rough. The mounting dovetails are rather wonky and even have several dents in them (I'm not sure how you actually make something like that!). There are two mounting stubs provided, neither of which is actually round.
However, for $20, it ain't bad. I'm not really bothered about linearity anyway, since my main use has been clocking surfaces (milling vise, holes on the lathe etc) where you're just looking for a small displacement. There doesn't appear to be significant backlash in the mechanism. Although this is made to look like a Mitutoyo product, the actual device is probably the standard Chinese dial test indicator knockoff, since it looks identical to others I've seen.
The dial is adjustable to set the zero position, and the contact arm can be bent through +/- 90° to accomodate different measuring positions.
It's a good addition to the magnetic arm.