This unique cocktail shaker features the patented Oxiloc system that makes it easy to seal and open the top. Simply press down on the opening in the silicone lid to create an airtight seal for shaking. Pull up on it too open for pouring. It's fast easy and foolproof. The body of the shaker features measuring marks in both fluid ozs. and millilitres and there's a built-in strainer in the lid. 12-oz. capacity, hand-washing recommended.