features of warning carbon dioxide level, large LCD with backlight, maximum, minimum reading display, data hold function, low battery indicator, wall-mounted and desktop design, auto power-off, reading internal memory (data record function), etc. Features: Multifunctional CO2 Detector: can measure the CO2 concentration(PPM), air temperature(°C/°F), humidity(%), barometric pressure(hPa, kPa, inHg, PSI), and it has perpetual calendar and time display. LCD Display Data Hold: 5.5-inch LCD screen with large black fonts that are clear and easy to view, easily ON/OFF the backlight by press the button on the top of the device. With data hold function to freeze the current reading. Max/Min Value Measurement Function: allows you to track the maximum and minimum of your readings for any parameter each time you power on the unit. Recording Function: after connecting the device to the PC and installing the software, you can begin logging data, the recording capacity is up to 9144 groups. Power Saving Function: powered by 4pcs 1.5V AA batteries, and it will shut down automatically after 10 minutes if there don’t have any operation. With low battery indicator to remind replace the battery. Dual Installation Methods: device design with two hanging holes and a foldable bracket, conveniently for hanging it on the wall or just place it on the countertop.