The sign is already highly recognisable to most people. You should ensure that there is one of these signs in every area that an alarm can be raised in this way. The sign would also glow in the dark, if there were a lack of lights, and would carry on providing people with instructions, as it is Jalite AAA photoluminescent. Fixing requires anything as simple as sticky pads, 'No-nails' type adhesive or double-sided tape.