This is a fun Steelume Sprinkler vintage sign.  Steelume sprinklers were introduced in the 1950s-1960s.  This sign was found recently, and by condition, looks NOS to us, take a look and see what you think.  It has some areas of minor paint fade, chipping, and the edge is rolled, so you can see it particularly around the edges, but the back and the graphics look good.  This is a painted metal sign.  
 
The water drop is such a throwback to that time period, and some of the technology that Steelume introduced is still used to this day.  
 
Measurements:
 
23 3/4 inches wide
17 1/2 inches tall