... ,TiCN,CrN ,ZrN or other same kind coating with hard diamond Configuration :ZJP-300 Roots pump ,2X-70&2X-8 ... ,TiCN,CrN ,ZrN or other same kind coating with hard diamond,which enhance the attachment with one another .This coating is also used ... to make watch,galsses,cooks and must be wear and hard. Cz ...