This is a fine-tuning spacer suitable for mountain and road bicycles, which can be used for the adjustment of the fork rake and stem. It is available in various specifications, such as 2mm, 3mm, 5mm, and a combination of 2/3/5mm, meeting different adjustment needs. This spacer is of reliable quality and can precisely fine-tune the bicycle stem, bringing a more comfortable and fitting riding experience to cyclists. Whether it's a professional rider making precise adjustments or an ordinary cycling enthusiast making daily adjustments, it is a practical accessory. It has good adaptability and can perfectly fit a variety of mountain and road bicycles, making the adjustment of your bicycle more convenient and fast. If you are troubled by the problem of bicycle stem adjustment, you might as well choose this fine-tuning spacer, which will add more convenience to your riding.