Molded from non-flammable Polycarbonate, pre-marked "EMERGENCY" with indelible printing, not to fade, bleed or rub off. High letters for easy identification. Virtually unbreakable, with high-structural rigidity, long-term form retention and excellent 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 - 3-1/8 in x 4-7/8 in.