Mitutoyo - measurement tool

Hi,
I found following measurement tool however do not have any manual. Does anyone know what is this used for ? Sounds like some strange micrometer 0-25mm, 0.01 accuracy, very old one however what are those glasses used for?

It's look like MICROMETER)))
It's measures some distance in milimeters. It uses in metal working field preferebly.
I don't see from the picture what it's purpose for.

i would look for a model number and research from there. i have personally never seen this type configuration but Mitutoyo is a top end brand from Japan so good quality. this brand makes my top 3 list and of those 3 on my list they are all high quality.