It can make those solid or powdery substances that need to be stirred by hand easily dissolve when shaken by hand, which is more convenient for us to drink.
Put the powder and water in the cup and just shake it by hand. Shake cups are mostly used by office workers, bodybuilders and students. Most people like to make milk tea, or protein powder, make milkshakes, peel and cut fruits into cubes and put them in milkshake cups.
Because the dissolved substance is solid or powder, it is difficult to fully mix with water or other dissolved substances without stirring and shaking.