Battery operated (3AAs included) Two LEDs - Red: Illuminates when in alarm mode, Green: Illuminates when DC power is present, normal operation Test/reset button tests CO alarm circuit operation and allows you to immediately silence the alarm Digital display continuously displays CO levels detected End of life alarm alerts user to replace the alarm after 10-years protection It has replaceable batteries 10 years sensor and warranty Warning! this CO alarm is not a substitute for a smoke or fire alarm.
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