A common goal electronic sounder for hearth, safety and industrial apps; the Sonos Sounder Beacon is Accredited to EN54. VIDs are well suited for use to be a supplementary warning device together with audible sounders but are not suitable for use in locations where a visible warning really should be https://www.firesense.co.uk/type/conventional-fire-system/conventional-sounders-vids-vads/