The Old Fashioned glass, lowball glass, or rocks glass is a short tumbler used for serving an alcoholic beverage

Alcoholic beverage

An alcoholic beverage is a drink containing ethanol, commonly known as alcohol. Alcoholic beverages are divided into three general classes: beers, wines, and spirits. They are legally consumed in most countries, and over 100 countries have laws regulating their production, sale, and consumption...

, such as whisky

Whisky

Whisky or whiskey is a type of distilled alcoholic beverage made from fermented grain mash. Different grains are used for different varieties, including barley, malted barley, rye, malted rye, wheat, and corn...

, with ice cubes (“on the rocks”). It is also normally used to serve certain cocktail

Cocktail

A cocktail is an alcoholic mixed drink that contains two or more ingredients—at least one of the ingredients must be a spirit.Cocktails were originally a mixture of spirits, sugar, water, and bitters. The word has come to mean almost any mixed drink that contains alcohol...

s, such as the Old Fashioned

Old Fashioned

The Old Fashioned is a type of cocktail made by muddling dissolved sugar with bitters then adding alcohol, such as jenever, whiskey, or brandy, and a twist of citrus rind. The name references the combination's age: it is possibly the first drink to be called a cocktail...

, from which it receives its name.

Old Fashioned glasses will usually contain 6 to 10 fluid ounces

Fluid Ounces

Fluid Ounces were a piano-based, power pop band from Murfreesboro, Tennessee that garnered a cult following for their critically acclaimed records, which featured a distinctive blend of hooks, varied musical styles, clever wordplay, and intricate, complex arrangements.-Inception:Seth Timbs had...

 (180 to 300 mL).

A double Old Fashioned glass contains 12 to 16 fluid ounces

Fluid Ounces

Fluid Ounces were a piano-based, power pop band from Murfreesboro, Tennessee that garnered a cult following for their critically acclaimed records, which featured a distinctive blend of hooks, varied musical styles, clever wordplay, and intricate, complex arrangements.-Inception:Seth Timbs had...

(350 to 440 mL).