... of plastic materials (POM, PP, PA, nylon), with excellent surface for sliding windows and doors 2) Inner ring is made of brass ... (POM, PP, PA, nylon) or metal material, with excellent surface for sliding windows and doors3) The inner ring is made of carbon ... office furniture (match drawer of desk and cabinet, etc), equipment (sliding door, alternation, covering, etc), copy machine, fax machine, printer ...