This Listing is for the:

Salton Yogurt Maker 5 Milk Glass Jars Model GM-5 ( JARS ONLY )

These "fire" very nicely in direct Sunlight.

These are made of "Milk Glass". Some sellers get plain White Glass confused with Milk Glass. You can see the firing around the tops of the cups brought out by the camera flash. You can also hold these up toward sunlight or CFL light bulbs to see them fire. 

If you have any questions, please ask before you "Bid" or "Buy".

THANK YOU!