The IST Shaker Bottle is the perfect shaker for mixing protein shakes and meal replacements. It has a unique design that has an internal screen that breaks up any lumps or clumps in the mix. The shaker allows the user to drink a smooth mix right from the bottle. The Inter-Sport Technology Shaker Bottle has many other practical household uses as well. It can be used to mix perfectly smooth gravies and sauces or to prepare eggs to the exact consistency for omelets or scrambling.