50 Pfennig

Ruhla's 1920 Notgeld issue belongs to the enormous wave of small-denomination emergency currency that flooded Germany during the post-WWI coin shortage — by mid-1920, hundreds of municipalities were printing their own 50 Pfennig notes simply because Reichsmünzen had vanished from everyday commerce, hoarded or melted. Ruhla itself was a small Thuringian town with a well-established watchmaking and metalworking industry, though that industrial character had no bearing on who authorized this issue.

The two signatories — Herb. Hoppert and König — were almost certainly local municipal officials, a common arrangement under which the Bürgermeister's office underwrote redemption rather than any banking institution.