For high-quality versions such as XTR, Dura-Ace, Ultegra, and 105, the inner cable is coated with PTFE (Teflon) to minimize friction losses and ensure smooth shifting operations. Shimano original parts maintain the precision and functionality of the components for optimal performance, maximum safety, and long durability. The quality of Shimano original parts is impressive. Each part is extensively tested and inspected. Shimano's internal requirements are often higher than industry standards and norms, providing safety and reliability. The segmentation into groups clearly categorizes performance according to the top-down principle, defining each Shimano performance level distinctly. Only Shimano original parts fit perfectly with Shimano components. The optimal fit facilitates replacement and meets the highest standards in all respects.