original american industrial single-sided cobalt blue cautionary or warning factory plant "no smoking" sign attributed to the safety first supply company, pittsburgh, pa. the reinforced wall-mount factory sign is comprised of 18 gauge iron with multiple coats or porcelain enameled baked on under considerably high temperatures. the "diamond" brand sign contains three of the four steel grommets used to protect the porcelain when mounting. excellent overall condition, considering age. measures approximately 13 1/2 x 9 inches.