NMC glow signs provide immediate visibility in sudden blackout situations. Unsurpassed in reliability, glow safety grade signs require no mechanical or electrical power source. Since these signs absorb and store energy from ambient light, they save energy and inexpensive to install. These 7550 Glo Directional signs are essential for establishing low-light emergency evacuation routes. MEA approved and compliant with the requirements of Nyc local law #62. Non-electric, non-toxic and non-radioactive. Designed for walls, ceilings, flag and conduits. Measures 8-inches length by 11-inches height.