What is 12oz?

As an AI language model, I don't have enough context to understand what specifically you are referring to as 12oz. However, 12oz is generally used as an abbreviation for 12 ounces, which is a unit of weight or volume of measurement used in the US customary and British imperial systems of measurement. It is equal to about 0.34 liters or 8 fluid ounces. This unit of measurement is commonly used to describe the size of canned or bottled beverages, such as sodas or beers.