It is a set of high performance oil seal and shaft guide. Silicone X ring (hardness 50 °) which is already becoming standard has been adopted as an oil seal. High sealing performance and low friction resistance are achieved at high level. The shock shaft's movement is not spoiled and the smooth feel brings out the maximum performance of the shock. In addition, the shaft guide was cut out by high precision machining processing and the thickness was 1.7 mm by repeated tests. By making it thinner than the general size, it reduces the preload applied to the X ring and reduces the resistance to the shaft. It is a shim for preload adjustment included, it is possible to set according to the shock case and oil you use. It adapts to shock of shaft diameter 3 mm including Tamiya TRF damper. ※ It may not be used depending on the structure of shock. Please check in advance and purchase.