Vintage 1950s Rare discount Hamilton, British Empire, Made in Hong Kong One Cell Fire Alarm

This is an incredibly cool, historical piece and I knew it was something when I found it but wasn't sure what. Very interesting to discover it is an early fire alarm! You can see where discount it was meant to be hung on the wall if you look at the back. It opens and closes with no issues but I don't know if it works or not since I don't have the specific battery required to test it. My educated guess, having dealt in antiques and vintage items for years, is that it would most likely work were you to have the correct battery. They made things to last back then! (I have a freezer from the '40s in my basement that still works better than my chest freezer in the garage from 2018!)