... Option:1.Bearing Material:carbon,chrome,stainless steel,iron,copper ect.2.Roller Material:POM,nylon,glass fiber,etc3. ... elegant design3. low noise, low friction4. High quality roller bearing 5. with high load-bearing apacity6.excellent rustproof ... groove ball bearings for carbon steel, bearing steel , stainless steel,non-standard bearing and injection molding roller and dysmorphism parts . Our ...