... combination, 3.Affordable and functional: 4.durable service 5.high quality WE are the professional technology-intensive industry,which is mainly ... long-life and excellent reliability. 1.Product imformations: Model No Non standard Bearing rollerBearing Material carbon steel ( carbon,chrome, ... of friction,5.Less force when closing the door,6.No wear, long life, durability and other characteristics. 4. ...