The Kidde Professional Series alarms can interlink with up to 23 interconnectible alarms, which means that all alarms will sound if any detect smoke or heat. This K30C Alarm detects heat of above 58°C (Class A2) and is recommended to be used in conjunction with interconnected smoke alarms. It is 230 volt mains powered, with a battery back-up in the event of a power failure. A Hush™ button allows temporary silencing of nuisance alarms caused by cooking or steam and resets automatically. In addition, this button is used to check the alarm operation. A lock-out feature prevents the alarm from being attached/fitted unless the back-up battery is installed. The alarm has an impressive sound rating of 85 decibel at 3 metres. For convenience, it has a front-loading battery door to allow the battery to be changed without removing the alarm. Technical specification:Model: K30CHeat detection: 58°CPower Supply: 230v mains-powered with 9V Alkaline battery back-upTemperature range: 0 to 40 degrees centigradeHumidity range: Up to 93% Relative Humidity (RH) non-condensingAlarm: 85 decibels.Kite marked to BS5446 part 2: 2003 CE tested and certified