... USI hydraulic oil seal(NOK) and all kinds of hydraulic cylinders, cylinder, complete seal with and without polyester skeleton oil seal ... , dust ring, metal hose, customizd non-standard rubber parts and molds, all kinds of high-pressure, low pressure pipeline ... manufaturing are undercontroled by Railway Ministry9.Designing and manufacturing all of oil seals, gaskedts,o-rings ,and so on. Import NAK seals ...