Every supplement users best friend! It removes the need for a blender and makes protein drinks or meal replacements readily available wherever you are any time, any place any where. Most shakers have a grill to assist the mixing but ours have a metal spiral ball which acts as a whisk in the shaket to ensure proper lump free mixing everytime. You will also find these shakers are made from a denser plastic than the usual ones which means they dont go smelly as quickly and are less likely to be damaged or warp at all if being washed at higher temperatures in a dishwasher. The way the lid screws on and the opening to drink out of are real quality compared to the others, these truly are the business.