lampbase,porcelain lamp holder,ceramic lamp socket 1)E27,E40,E26 ... /Iron/Aluminium Edison screw CE and ROHS E14 Porcelain lamp holder 1.E10,E12,E14, E26,E27 ... ,E39, E40 lampholder,porcelain knife switch,fuse unit series etc.2.Metal: ... E14, E27, E40 Series etc. Body MaterialPorcelain/ ceramic Metal MaterialScrew shellaluminium/iron/copper/brassCenter connectCopperWire connectCopper/ ...