Compatibility across multiple thru axle standards: adjustable length with spacers to fit 135, 142, and 148 mm hubs, and frames up to 176 mm wide, making it suitable for a range of bike models. Secure mounting for trainer use: tapered heads on both ends provide a reliable fit in most trainer mounting holes, ensuring a solid connection during workouts with minimal risk of slippage. Durable, construction: crafted from 6061 aluminum alloy to withstand rigorous use while maintaining structural integrity over time. Frame protection during intense workouts: the MTB Road Bike Thru Axle Spacers match the shape of frame dropouts to help guard your bike frame from potential damage. Use scenario 1: Switching between road and mountain bikes in a shared home gym, accommodating different hub sizes without changing hardware. Use scenario 2: Regular indoor trainer sessions across multiple bikes with thru axles, ensuring quick setup and secure mounting every time. Use scenario 3: intensity interval training where a stable, secure connection is essential to prevent movement and protect the frame.