I used to own a tool that looked like a large pen/scribe. The Scribe point when "released" would protrude and you could put it into a hole (for really small diameters) and when the taper on the scribe bottomed out on the hole you could read in a little glass window up on the shaft what diameter the hole was. It has walked away and I have no idea what it's called and all the things I'm trying to call it on the net come up dry. I suspect it's a QC type tool and thought it would be called a hole guage.
Could someone point me in the right direction on this?