A biter bar, also called a biter stick, is used to figure out if the curling stone ends up in the appropriate target area. It is an important measuring device in the sport of curling. There are two ends of a biter bar. At one end, it is placed in a post at the center of the target area. The other end turns around the target area and determines if the stone is a biter. The biter bar proves if the stone is in the target area, even when the stone does not look like it is touching the ring.
In the picture below, you use a biter stick to measure the stones.