... .Materials :The rings and balls made of full ceramic material: ZrO2, SisN4 and Sic as a standard structure, the cage made of ... PTFE, GFRPA66-25, PEEK etc.All kinds of ceramic ball bearing ... have in stock. Such as: 606, 607,608, 6205, 6800..... SIC Ceramic Ball Bearing 605/606/607/608/6000