Stamp, militar or civil?

[Mike TM]

Hello, I have this curious little stamp. I don't know if it's militar or civil use. Any idea? The box is made of baquelite.

Thanks in advanced.
Mike

[Nick Komiya]

You need to stamp it to be read, as my brain cannot deal with upside down mirror images, but this would be a normal non-military stamp that any family has. It can be from any period