The sign is AAA photoluminescent and this means that it will continue to glow, even if the lights go out. The sign will be seen best if it is placed at eye level. It will then be able to act as a warning to people. Use this sign to make all visitors to your building aware that it is an automatic fire door and to keep clear. Fixing requires anything as simple as sticky pads, 'No-nails' type adhesive or double-sided tape.