These medium glass bearings are designed specifically for use 
with standard sized Richard Glässer Pyramids but they may 
also fit and work with other brands, especially those made 
during the GDR times... "Expertic" labeled brand.  

Single Glass Bearing - Made in Germany by RG
Erzgebirgische Volkskunst 
Richard Glässer GmbH Seiffen
12-13mm in diameter - Color may vary
This cup fits 90% of German Pyramids!