Feature: 1. LCD display is backlit and easy to read, which can shows date, time, maximum and minimum values, etc. 2. Designed to measure the concentration and ratio of carbon dioxide. Air temperature and humidity can also be measured.While there is real‑time monitoring of carbon dioxide, temperature and humidity. 3. This series of products can monitor carbon dioxide, temperature and humidity in real time. These measured parameters are very important to guide us to understand the surrounding air quality. 4. Users can use these products to monitor the ambient air and find some problems in time. 5. These products are suitable for offices, classrooms, factories, hospitals, animal and plant breeding, environmental monitoring, hotels, bathrooms, kitchens, automobiles, and any other places that need to be tested. 6. Sound alarm and small face icon indicate air quality, as an useful instrument for monitoring indoor air quality. Specification: Item Type: Carbon dioxide detector Product Material: Plastic shell Product Model: TL-2000 Measurement Accuracy: ±50ppm ±5%rdg (0~5000) Accuracy Class: 0.05% FSO Measuring Range: 0~9999(out of scale) LCD Display: Approx. 12 x 7.5cm / 4.7 x 3in Maximum Working Pressure: 137.9 Measurement Objects: Carbon dioxide, temperature, humidity, atmospheric pressure, altitude Voltage: 6V Power Supply: 6V Battery: 4 x AA batteries (not included). Package List: 1 x Carbon Dioxide Detector 1 x US Plug1 x Data Cable1 x Compact Disk1 x User Manual