This is a vintage Pyrex butter dish in the "Old Town Blue" pattern, also known as Blue Onion. Pattern Duration: The Old Town Blue pattern was produced between 1972 and 1982. Material: Made of durable milk glass. Dimensions: Approximately 6 7/8 inches in length and 2 1/4 inches in height. Significance: It was released as part of a series compatible with Corelle dinnerware to fill gaps in tableware sets. Text if interested. Asking $13.00