A stainless steel cocktail measure, also known as a double jigger, is a bartending tool used to measure and pour precise amounts of spirits and other ingredients when making cocktails. The most common size of a cocktail measure is 15/30ml, with one side measuring 15ml and the other side measuring 30ml. Drink Botanicals Irelands double jigger is made of stainless steel, which is a durable and easy-to-clean material that is commonly used in barware. The two sides of the jigger are typically different sizes, with one side being larger than the other. This allows the bartender to accurately measure and pour different amounts of ingredients, depending on the recipe.