Original 1940 Karlsbad sipping cup. Used to sip on mineral water at spas. The text is fading and a bit worn. It does need cleaned, but is in generally good condition.
Karlsbad (now Karlovy Vary) is a spa town in Czech Republic. It was part of the Sudatenland that was annexed to Germany in 1938. This would be for drinking the "curative" spring water; cups like these are still used. The shape is specially designed to preserve the temperature and CO2 content.