"Smoothness" and "toughness" are important elements of high-quality driving that SPOON always pursues. Utilizing the technology and experience cultivated through many years of endurance racing, we have created a drive shaft that enables smooth and smooth running and high durability. The micron-level clearance created by thoroughly polishing the inside of the case and finishing it to a mirror surface reliably improves grease lubrication and enables low-sliding and low-vibration drive. The smooth joint prevents damage due to seizure and can also obtain high durability.