55000-122APO is a Heat Detector, monitors temperature by using a dual thermistor network which provides a voltage output proportional to the external air temperature. There are 12 heat detectors in the Series 65 range designed to suit a wide variety of operating conditions. It is suitable for guest houses, cafes, dusty environments, restaurants, retails and small to medium buildings.- Can be used for applications where smoke detectors are unsuitable- Ideal for environments that are dirty or smoky under natural conditions- Wide operating voltage- Flashing LED and magnet operated test switch option- 3-Year warranty- Electrically and mechanically compatible with Series 60