Looking for a CO-9X alarm replacement? With the latest sensing technology, a clear loud alarm and BSI Kitemark approval, the FA3820 offers the highest level of CO detection for your home and replaces end-of-life CO-9X alarms. Intelligent CO sensing technology enables the alarm’s high sensitivity mode to be activated if it predicts CO levels will increase to or above 180ppm for a quicker alert. Advanced electrochemical sensor detects and provides a warning to low levels of carbon monoxide, and will provide a ventilate alert as this increases Press the test button once for a complete alarm test with a quieter audible alert or press twice for a complete test with full alert Pressing the large test button in the event of a low battery warning will activate the sleep easy feature which silences the low battery chirp for 8 hours A 10-year battery is sealed within the alarm which will offer protection for the lifetime of the device, without needing to change the batteries Suitable for homes in England, Wales and Scotland (under new guidance) FireAngel alarms are rigorously tested to ensure unrivalled quality and longevity and come with a 5-year manufacturer’s warranty for peace of mind Rigorously tested in-house and third party approved and certified to Kitemark standards