Feature: 1. Carbon dioxide detector, with 5.5in backlit LCD display, large black fonts are clear and easy to read. 2. Measure CO2 concentration (PPM), air temperature (℃/℉), humidity (%), atmospheric pressure (hPa, kPa, inHg, PSI), with perpetual calendar and time display. 3. Maximum/minimum value measurement function, each time you turn on the device, you can track the maximum and minimum values of any parameter. 4. With carbon dioxide warning level, support data retention function, automatic power off, internal memory reading (data logging function). 5. Powered by 4x1.5V AA batteries (not included), if it cannot be used, it will automatically shut down after 10 minutes. With a low battery indicator to remind you to replace the battery. 6. High accuracy, suitable for use in a variety of environments, indoor, outdoor, office, etc. 7. Double installation method, the equipment with 2 hanging holes and folding bracket, is very suitable for wall hanging or countertop. Specification: Item Type: CO2 Detector Material: ABS Carbon Dioxide Range: 0-9999 (Over Scale) Accuracy: ±50ppm Reading ±5% (0-5000) Response Time: 10 Seconds Temperature Range: -10-70℃ (14-158℉) Resolution: 0.1℃/℉ Accuracy: ±0.6℃/℉±0.9 (0-50℃/ 32-122℉), Others ±1.2℃ Humidity Range: 0-99.9% Resolution: 0.1% Air Pressure Range: 10-1100hPa / 1-110kPa / 0.29-32.48 InHg / 0.15-16.00 Psi Resolution: 1Pa / 0.1kPa / 0.01 InHg / 0.01Psi Data Record: 9144 Groups Working Conditions: 0-50℃, 0-95%RH Storage Conditions: -20-60℃, 0-99%RH Screen Size: Approx. 120x70mm / 4.7x2.8in Storage Box Size: Approx. 250x205x68mm / 9.8x8.1x2.7in Power Supply: 4 x 1.5V AA Battery (Battery Not Included) or the first output 5V AC adapter Product Size: Approx. 160x122x28mm / 6.3x4.8x1.1inWeight: Approx. 881g / 31.1oz How to Use: Get the product, install the battery (not included), and then use it; the user can adjust the use of multiple functions. There are multiple buttons on the back of the product, from top to bottom; from left to right: 1. Switch temperature unit: ℃ / ℉ 2. Switch atmospheric pressure: hpa, kpa, inHg, PSI 3. Data hold button 4. Maximum/minimum reading function 5. Non-automatic shutdown button 6. REC button 7. Record button 8. Power button This product can also be connected to the supporting 5V AC adapter for charging without installing a battery; when recording multiple data, the CD can be used, and the computer side operation is required. First use the USB data cable to connect to the computer, and the computer side needs to download the connection Timely software application can be matched with the carbon dioxide instrument, and the data can be exported after successful connection. The connection steps can refer to the manual, there are detailed operation steps. . Package List: 1 x CO2 Detector (Battery Not Included)1 x USB Cable1 x 5V AC Adapter1 x CD1 x Manual Note: 1. Please allow 0‑1 inch error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.