Vintage TFA Analog Hygrometer, West Germany

It has a case with brass ring. It does not require any power source for its operation.

It's in good condition with some cosmetic wear due to age. There are some tiny wear on copper frame around the glass surface.
There is no any crack or damage, missing or changed part. Whole pieces are original.

Dimension: 10x10x4 cm
Weight: 50 g

Buy it: 
https://www.ebay.co.uk/itm/295696739769?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=qch9zq1zslg&sssrc=2380676&ssuid=qch9zq1zslg&widget_ver=artemis&media=COPY