That’s exactly why I’ve told him & his friend (who has several of those) to be extremely careful with them multiple times, especially since the amount of radiation in them is way higher than in modern ionization detectors.
New wall decor! 1964 E.W Bliss-Gamewell drawing for a Breakglass Pull Guard assembly for the old “Cottage Shell” style masterboxes, this was a birthday gift that was found at a antique store for a good price issued #2 1-27-1964 with signatures.
Very nice! No clue how something that unlikely to be found at an antique store of all places was discovered at such a location though!