If this sign is not displayed, people will not realise and may enter an area regardless. This sign will even glow in the dark if the lights go out, this is because the sign is Jalite AAA photoluminescent. Use this sign to restrict access to all of the areas that are to be kept for authorised personnel only. Fixing requires anything as simple as sticky pads, 'No-nails' type adhesive or double-sided tape.