micrometer stand fits 0-25mm and 25-50mm micrometers,

one version has extra grip in the form of groves/teeth, while the other has smooth jaws.

requires M10 x 50mm bolt (can be longer if needed) and nut (wing nut or other thumb screw recommended).

the bolt is a tight fit so use some force, I found screwing the bolt in and using the nut to get it into final position worked well