The 15cm Bike Headset Fork Spacers for 28.6mm forks are made of robust aluminum alloy, ensuring durability and strength. These spacers are designed with precise measurements, perfectly fitting into 28.6mm forks, providing a secure and comfortable riding experience. The herringbone design of the spacers enhances durability and reduces the risk of wear and tear. The aluminum alloy material is lightweight yet robust, making them easy to install and maintain. With their high-quality and cost-effective design, these bike headset fork spacers are a must-have for any cyclist looking to enhance their bike's performance and comfort.