Here is several neon sign sockets that were used on various signs. I really love the colored ones that were glazed to match a sign. L-R- marked with just a 4 and a P white porcelain, Next marked 1 and 502 white porcelain, No Name Cobalt Blue glazed, No Name white glazed, Last marked 4 and 2 on top, bottom marked Cat. GE 172/G.E. Co. U.S.A. white porcelain.