original american vintage industrial c. 1930's single-sided green porcelain enameled die cut steel "high voltage" cautionary or notification sign designed and fabricated by the ready-made sign co., new york city, ny. the two signs were found mounted against an outdoor steel chainlink fence surrounding a transformer. both signs exhibit a nicely aged surface patina from decades of exposure to the elements. both signs together measure 8 x 6 1/2 inches.