FireAngel FA3313 Replaceable Battery Detector Carbon Monoxide Alarm Advanced electrochemical sensor detects dangerous levels of Carbon Monoxide ( CO ) in your home and alerts you with a clear, loud alarm. As well as being calibrated and rigorously tested in-house the alarm has been third party approved through the British Standards Institute (BSI) and is Kitemark certified. The unit has been designed to either be wall mounted or left portable so you can take it on holiday for protection on the go. It's also suitable for caravans, motor caravans and boats. The device is supplied with 2 x AA batteries, which can be replaced as required when the alarm provides the low battery warning sound. Pressing the large test button in the event of a low battery warning will activate our sleep easy feature which silences the low battery chirp for 8 hours. Suitable for homes in England and Wales, including rented properties. Not suitable for Scottish homes under the new regulations. The FA3313 detecto