The Parmelee Transportation System was a livery and cartage company established in 1853. This piece is from the 20th century when Parmelee provided taxicab service in cities where it had the franchise rights to do so. We assume this piece is from the 1920s as Parmelee was acquired by Maurice Markin of the Checker Motors Corporation in the 1930s and remained under their control until the mid-1960s. This piece is slightly convex and 2" wide. The states are done in blue enamel although there is enamel missing from the northeast area. Reverse has pair of .5" long threaded posts each with a nut which allowed it to be fastened to a driver's hat. Only example we've seen.