ink pen calipur

Sometimes you find a useful tool that is nothing more than a promotional give way.
I've had this pen for probably 10 years now it's come up MIA several times but somehow I always seem to relocate it
I've used it thousands of times to measure the ID or OD of something in a scrap yard when I have forgotten to carry along a real caliper
Funny thing is it will produce a surprisingly close reference the ID is a direct reading for the OD I simply add 4 mm to the reading I can usually tell within .5 mm a and if I put my glasses on I can get that to .2 mm but normally I am just interested in the nearest whole MM
Attachment 18129
Attachment 18130
I got it at a trade show handed out by the Fischer fastener company. I think that I'm on about the 3rd refill now from doner pens

Trash to one, Treasure for another. How many novelties exist that original intent was only to attract attention; yet live on as useful devices?

I used to attend several trades shows each year. many was the time I would have to pay a couple hundred Euros in excess baggage to carry the samples and literature I had collected during the 2 to 3 day shows. 1 year I did a month long trade show marathon 1 in Spain 2 in Italy 3 in Germany 1 in Sweden then to Turkey then from there. I finally wound up in the far East where I attended 2 more then back to Kuwait for a few days before I decided to take a month long vacation with the wife to Australia where I had thought I might get to relax for a while. So much for that she had never been to AU and wanted to see all of the places I had been telling her that I had visited on my previous trips there 10,000 miles worth of driving and 7 plane trips later I really needed a vacation