There are two types of Boston shakers that bartenders use: the cobbler shaker and the French shaker.
The cobbler shaker is the most common type of Boston shaker. It consists of three parts: a tin, a mixing glass, and a lid. To use it, you simply add your ingredients to the tin, then put the lid on and shake it vigorously. The advantage of this type of shaker is that it's very easy to use and clean.
The French shaker is slightly more complicated than the cobbler shaker. It consists of two parts: a mixing glass and a metal cup. To use it, you place your ingredients in the glass, then put the metal cup on top and shake it vigorously. The advantage of this type of shaker is that it's able to create a stronger cocktail since there's less air in the mix.