Molded from non-flammable Polycarbonate, pre-marked "EMERGENCY" with indelible printing guaranteed not to fade, bleed or rub off. High letters for easy identification. Virtually unbreakable, with high structural rigidity, long-term form retention and superior impact and abrasion resistance. Screw-catch feature holds mounting screws captive and simplifies installation. Matching screws provided. High gloss finish is soil resistant. Mid-size - 3.125" x 4.875".