This 12 oz. mug has a miniature battery operated propeller at the bottom of the well that spins at 3,000 rpms - at the touch of the button located at the bottom of the handle. With the automatic stirring, the need for stir sticks is eliminated. This is an ideal solution for hot chocolate that clumps at the bottom of a cup or to keep honey mixed thoroughly into tea. The mug comes with a useful lid to keep contents from spilling or to be used as a coaster. The mug requires two AA batteries.