These gadgets are typically installed in buildings as well as other structures to alert occupants to the presence of a hearth also to aid evacuation. Dr Zzeus Q&A: If hearth alarm indicator products never meet the needed specifications, would be the process compliant? Visual Alarms: Employ light-weight to signal emergencies, https://www.firesense.co.uk/type/conventional-fire-system/conventional-sounders-vids-vads/