For the slight difference in the length of the left and right legs: the stackable adjustment design provides an adjustment range of 1mm-5mm. Helps keep your foot/ankle/leg in a more comfortable position during . Greatly improve your pedals, durable material nylon can increase friction and effectively prevent slipping. Easy installation: Comes with 2 size mounting screws, which is convenient and quick, and will not damage the locking pedal. Colour: black Material: nylon + metal Package Contents: 1 * 1mm spacer 2 * 2mm spacers 6 * screws Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.