American Shaker

The American Shaker sometimes called the Boston is perhaps the most used style of shaker around the World. It comes in two parts, one part glass and the other in stainless steel. Bartenders tend to make their cocktails into the glass part, obviously to see the mix before placing the cone over the top to shake. This shaker is a perfect example for using an external strainer to hold back the ice after shaking and when straining the cocktail into the glass.
Boston Shaker

The Boston Shaker sometimes referred to as the French Shaker, has two parts and requires the use of an external strainer when straining the cocktail into the glass. This example shows that it has two silver or stainless steel cones. This shaker is much preferred by many professional bartenders as it chills the drink quickly, therefore less dilution and time. It is similar to the American Shaker which also has two cones, difference being, that one cone of the American is made of glass. There are many sizes and styles of Boston Shaker depending on the volume of cocktails being made. Many bars have a whole range of sizes to suit every occasion.
Standard Shaker

The Standard Shaker is very popular in Europe and Asia and is in three parts, the bowl where you add your ingredients, the top which contains a built in strainer and a cap to cover the strainer to prevent leakage when shaking. This is an excellent shaker for a bar that only makes a few cocktails now and again. Some bartenders will knock out the strainer part and use it as a two part shaker like the Boston and strain using an external strainer. This shaker is Ideal for the home bar.
External Strainer

An External Strainer is used in conjunction with your shakers, to hold ice back from entering your cocktail. Usually made from stainless steel, it has a spring which fits tight to the inside of the cone of your shaker or mixing glass allowing enough space between the lip of your vessel for the liquid to run smoothly, There are many types of strainers (see strainers), and they are mainly called after the more popular model "the Hawthorne", but most bartenders use the "Angel trainer which has wing type lugs that sit on top of the vessel being used and a finger hold on the surface to allow you to control the flow. However, if not used properly, the liquid will get trapped and spill out through the air holes and miss the glass.