The On Track Assy-RR Cassette QR Axle 145mm is designed for quick and efficient wheel changes, making it an essential component for both road and mountain biking enthusiasts. This axle is compatible with 7, 8, and 9-speed cassettes, ensuring versatility for various bike setups. With its lightweight construction and quick release feature, it enhances performance while providing ease of use. Please note that bearings are not included, allowing for personalized customization to suit your specific needs.