Well, it's British… 1939… Brand new. These were rare enough that I can say it's worth 100.
- Fact 1: The gas mask was first patented in 1848 by Lewis P. Haslett.
- Fact 2: Mass production of gas masks began during World War I.
- Fact 3: WWII era gas masks contained blue asbestos in their filters, a substance used until 1956.
- Fact 4: The first gas mask ever used was as simple as they come: a sponge.
- Fact 5: Because dogs were frequently used on the front lines during World War I, canine gas masks were developed alongside human ones.