The obverse features an effigy of Libertas, the Roman goddess and embodiment of Liberty. It depicts a female head looking right, with a ribbon in her hair, wearing a diadem with the text LIBERTAS on it. The reverse shows the value 20 (only a numeral, no text) within a wreath of flowers (Alpine roses). This original reverse has remained unchanged since 1850 retired legal tender status in January 1, 2004
And the letter B Meaning - Mint B Bern, Switzerland (1225-date) https://en.numista.com/catalogue/pieces178.html
Obverse Head of Libertas (the Roman goddess and personification of Liberty) facing right, with braided hair tied in a ribbon, wearing a tiara bearing the inscription "LIBERTAS".
