The ultimate workhorse of a Boston Shaker. Seals tightly, opens easily, and looks ridiculously good on your home bar or back bar. It’ll be your trusty cocktail sidekick for years to come! Cups are 28 oz / 825ml and 18 oz / 525ml. Seals tightly & Opens easily (but only when you want it to!) Made from Stainless Steel 304 (That's the high-quality, food-grade kind). Weld: Circle-welded, so the bottoms will never fall off!