unique and hard to find early american single-sided industrial "high voltage" danger sign designed and fabricated by the ready-made sign company of new york city, ny. the vintage cautionary sign was salvaged from an old mine-shaft located in pennsylvania. the sign contains an oversized solid red dot (universal symbol of danger) contained within a diamond divided into four sections. the word "danger" is surrounded by a multitude of lighting bolts. the surface exhibits typical surface wear with only minor loss of porcelain along the edges. the die-cut steel sign contains four screw holes for mounting purposes. 13 x 6 inches