A bi-directional rotating bezel is a feature found in some watches that allows the user to both count up and count down the time. It typically consists of a ring around the face of the watch with markings that rotate around the face. It is usually used as a timer and can be used to count down a specific amount of time, or to keep track of elapsed time. The bi-directional feature allows the user to rotate the bezel either in a clockwise or counterclockwise direction, making it easier to use for a variety of purposes.