A general function electronic sounder for hearth, security and industrial apps; the Sonos Sounder Beacon is certified to EN54. Put only, this direction makes it apparent that the place a visual indicator is applied being a primary alarm, it needs to be a VAD Licensed to EN fifty four-23 Except https://www.firesense.co.uk/type/conventional-fire-system/conventional-sounders-vids-vads/