A detector with an electrochemical sensor detects CO (carbon monoxide) levels and signals pollution. The current CO level is constantly displayed on the screen. Low CO concentration warning. Functions of the test button: 1) to check the device and battery - in standby mode 2) to turn off the alarm for up to 10 minutes (mute). Alarm volume >85dB. Functional temperature range -10/+40´C, permissible relative humidity <93%. After 10 years of use, it will automatically notify you of the end of its working life. A detailed user manual in Estonian is included in the package. A set of two screws and a dowel is included for easy installation. Batteries 3XAA are not included. Complies with European Union standard EN50291.