SALE! Vintage Crucible Steel folding "Intense light absorption" pocket eyeshield

Description

This is a very unusual item.
A folding/ pocket eye protecting device. there is a pocket in which there is a special piece of glass.  it is very dark.
There is a spare glass in an envelope labelled "intense light absorption Blue glass shield" and it has the word monarch etched on it in a corner.  one of the pictures shows it out of the envelope in front of the main unit.
The case says crucible steel, where both my father (late 1950s to early 1962) and grandfather (40s until 70s) worked,  i am not sure whose this was.  i think it was to be able to look at the steel as it was being poured out of the ovens.  my dad was a metallurgist there who had to take samples of molten steel.
This particular piece does not look like it was used much at all.
nice as a collectible or to use but i cannot say how it is to be used.
shipped insured and priority.
IF YOU ARE INTERESTED IN BUYING MULTIPLE LISTINGS LET ME KNOW AND I WILL TRY TO WORK A DEAL WITH YOU in addition to combining shipping.