Phd mixball shaker works on the same principle as a wire whisk it has a wire ball that you drop into the cup along with all the other ingredients and shake the wire ball moves freely through the bottle as you shake it and gives you a fine lump free creamy drink r r key benefits r r r r its dishwasher safe r r perfect for double serving protein shakes r r no plastic mesh r r its easy to clean r r non drip screw top lid