These Optimum Nutrition large shaker cups cannot be found at many places in the UK. Mixing-up even the largest and thickest protein or meal replacement shake is an easy task for this monster shaker, it really is for the hardcore gym goers and weekend warriors. Each shaker cup has an Extra-Large 946ML capacity and a 3 1/4″ opening at the top that makes adding full-size ice cubes a simple task. There is also deep-skirt cap that screws down tight to prevent any leakage and also a tapered bottom that fits into most car cup holders. And, unlike some of the cheap knock-offs on the market, this shaker is solid enough to survive dozens of cleaning’s in the dishwasher.