These little Noga knock offs from eBay are pretty good units once you get them up to standards.
Problem 1. Dovetail does not fit any of my DTIs.
Solution Used a small triangle file to make the darn thing fit my indicator dovetails.
Only takes 10 minutes to complete. You can of course use the round hole to
hold a rod with a dovetail swivel attached for your DTI.
Problem 2. Base of indicator is not flat.
Solution Use a flat stone to flatten it. I used an oil stone first and finished with a 1500 grit diamond brick and it only took about
15 minutes to flatten it. The magnet is not super strong but it holds a small indicator quite well.
Over all I think the price is right and well worth the little effort required to get them into shape.