vintage machinist indicator mystery

Description

I am not exactly sure what this is. The dial is marked 0 to 25 and the indicator moves freely when the plunger at the tip of the shaft is depressed, and then returns to zero. If you know what this is please let me know.
Examine the pictures closely, I take care to show features and flaws.
If there is an issue please contact me and I will resolve it.
I auction vintage, new, and antique tools for machinists, woodworkers, & mechanics to use and collect.
New auctions start Thursday evening and will run 10 days.
Low starting bids.
No buy-it-now price.
No best offer.
No reserve.
Auctions end on Sunday evenings.
If paid before 4PM Monday, items will ship Tuesday.
If you are bidding on multiple auctions and want combined shipping, send a message after the auction ends with which items you have won, Don’t pay until you receive a new invoice with combined shipping.
Returns are accepted; please contact me.
I hope you bid,
Michael