The Tacx Thru Adaptor 12mm x1.0 is an essential accessory for mountain bikers looking to use their bikes with Tacx classic trainers. This adaptor features a metric fine thread, ensuring a secure fit for hubs with an axle skewer attachment of 142x12 mm, making it compatible with various DT Swiss and Shimano models. By replacing the standard axle skewer, it allows for seamless integration into your training setup, enhancing your indoor cycling experience.