Description Use with smart device and free TPI View smart probe app Measure 0 to 999ppm CO Conduct Tests of CO Levels In Ambient Air Confirm Proper Operation of Alarming CO Detectors in Households Check For Proper Installation of Ventless Gas Fireplaces, Furnaces, and Other Combustion Devices Low Battery Indicator.(Red LED flashing on.) Battery type 3X AAA Bluetooth 4.2
