Beautifully made adjustable crank arm shorteners for differing leg lengths or restricted mobility, or for kids. The pedal can slide along the crank arm for infinite adjustment, changeable as circumstances dictate. Sold individually, each crank arm shortener can be used for the left or right crank arm. Use the hole with the "L" for the left crank arm, the other (unlabeled) hole for the right. If you need a pair please order 2.