A basic reason electronic sounder for fire, protection and industrial purposes; the Sonos Sounder Beacon is certified to EN54. Provision of telephones compatible with hearing aids, marked Using the normal ear and ‘T’ symbol and Outfitted with inductive couplers and volume controls. This small thing has mighty points heading for https://www.firesense.co.uk/type/conventional-fire-system/conventional-sounders-vids-vads/