Again, moderators if this is inappropriate for this forum, please move it. Can anyone identify this device? It came to me in a lot of guns, ammunition, and accessories that I bought in an estate sale several years ago. There was a great deal of military paraphernalia in the lot. It was a long time before I associated the two different pieces as belonging to each other because they were in different boxes and it was a while before I got around to reducing all of the stuff down to one small pile. Then I noticed that the threads on the cartridge portion would fit into the threaded hole in the little box. The cartridge portion has what appears to be a primer in the threaded end that is about 8-10 mm across. The other end is sealed with what appears to be a reddish wax substance like a blank cartridge. The box is about the size of a penny match box. Inside it has a spring loaded mechanism that appears to be a firing pin. When the firing pin is pulled back, a pin can be inserted through holes on corresponding sides of the box, locking the firing pin in an "armed" state. No pin was in the lot, so in the pictures, I am using a finishing nail for demonstration. My best guess is that it is some kind of trip wire alarm device. The "cartridge" would explode when fired by the firing pin in the triggering device when a trip wire was pulled, extracting the pin and allowing the spring loaded firing pin to strike the primer. There are no markings whatsoever on the device. I have included one pic below with a quarter for size perspective. What is it? Who manufactured it? Is it military or "prepper"? Anyone????