Embossed Metal Canister.... Another Humidor ?/ Marked Germany

This came from Salvation Army this morning. I thought it was unusual because when I opened it I saw a heavy circular disc inside with a knob. So it was used to keep something compacted. The two conclusions I could come up with is tea or tobacco. Either way I think it's to keep something fresh. I peeled the green felt off the bottom and found the Germany mark with a little image above it. Not very easy to see what it is. If this is a humidor or a tea caddy looks like the start of another collection. -Mike-