This is a heavy steel and porcelain one-sided Coca-Cola sign, with a lithography mark dating it to 1927.  I have owned several of these and think they are some of the most striking porcelain signs ever to be used by Coca-Cola.  The colors of this sign are bright.  I have almost as much in this sign as I am asking, but I'm paring down my collection of well over 1000 signs that I've collected over the years and simply don't have room to properly display all the signs and it doesn't seem right to keep them crated up.  The green sticker ("27") in the lower right hand corner is part of my inventory system and not part of the sign.  The lithography marks on the lower right read "MADE IN USA COPYRIGHT 1927 COCA COLA COMPANY".  See a version of this sign in Bruner, Porcelain Enamel Advertising, 1999,p.35.