Reverse Swirl Glass Butter Base in Canary or Vaseline Opalescent.  Originally made by Buckeye and later production by Model Flint.  Circa 1900.   The Diameter where the top fits is about 5 1/4" and the Ht. is 2".  Very good clarity and in Excellent Condition with no chips or flakes.  If you have the canary opalescent butter lid to this pattern, this is what you need to complete the butter.