What kosher certification is a Circle U?

There is no kosher certification called "Circle U." It's possible you are thinking of a different symbol or organization.

To help me understand what you're looking for, could you please tell me:

* Where did you see the Circle U symbol? (On a product label, a website, etc.)

* What kind of product are you looking at? (Food, cosmetics, etc.)

* Can you describe the symbol in more detail? (Is it a circle with a letter U inside? Are there any other symbols or letters present?)

With more information, I can try to figure out what kosher certification you're interested in.