Features: Supper large LCD simultaneously display and log Carbon Dioxide Level, Temperature,relative humidity, Calendar (Y/M/D) and Time (Clock) 12700 data logging memory Warning CARBON DIOXIDE LEVEL Stable NDIR sensor for Carbon Dioxide concentration NDIR (Non-Dispersive Infrared) WAVEGUIDE TECHNOLOGY WITH ABC (Automatic back-ground Calibration) High and low threshold setting Back-light function, Recall Max and Min reading and Long time drift compensation. Specification: Large LCE display: 3.5 inch (8.9 cm) LCD display with backlight Logger mode: keypad statistics/stop, now, plan, real time and flip Carbon dioxide range: 0~9999 (out of range) Accuracy:±50ppm±5%rdg（0~5000） Response time: 10 seconds Temperature range: -10.0~70.0℃(14~158℉) Resolution: 0.1℃/℉ Accuracy:±0.6℃/±0.9℉（0~50℃/ 32~122℉,other±1.2℃ Humidity range: 0.1~ 99.9% Resolution: 0.1% Accuracy:±3%（10~90%） Record memory: 40,000 Working conditions: 0 ~ 50℃, 0 ~ 95% RH Storage conditions: - 20 ~ 60℃, 0 ~ 99% RH Sensor life: normally 15 years Storage temperature: -40~70℃(-40~158℉) Power supply: 1A output 9V AC adapter or 2 pairs of 1.5v AA batteries (not included) Color: white Material: ABS+TPU Size: 14*10*4cm/5.5*3.9*1.6in Weight: Approx.794g/28oz Package list: 1 x tool box 1 x carbon dioxide detector(batteries not included) 1 x USB data cable 1 x CD 1 x English user manual 1 x cardboard box