Boston 400ml Cocktail Shaker Whether you’re shaking a margarita for one, or you’re impressing friends at a cocktail party, this Boston cocktail shaker will have you whipping up classics, just like the professionals. This shaker follows the two-piece Boston design loved by pro mixologists. The difference is a couple of beginner-friendly features, which help tackle the tricky bits, so you can concentrate on your flair. Firstly, the glass tumbler is marked with six classic cocktail recipes. To make a perfect piña colada, or a first-class cosmopolitan, all you have to do is add your ingredients up to the marked lines, and shake. Secondly, there’s a silicone rim on the tumbler, which fits neatly into the stainless steel cup, so you don’t have to worry about any liquids escaping as you flip, twist and shake!