Feature: 1. 4 in 1: Multifunctional air quality detector real time monitors CO concentration, CO2 concentration, temperature and relative humidity in the air. Large digital screen with backlight, clear and easy to read, support alarm function. 2. High Accuracy: Using electrochemical sensor, plus high performance chip, detection is more accurate, higher accuracy, and the accuracy up to 1PPM. 3. Quick Heat Dissipation: With multiple ventilation holes, which accelerate the convection between the air and the detector, to achieve effective detection and provide a nice heat dissipation effect. 4. Built in Battery: Equipped with 2000mAh high capacity rechargeable battery, low power consumption and long endurance, no need to replace the battery frequently. 5. Wide Application: Lightweight and portable, it is suitable for home, office, school, warehouse, agricultural planting, etc. No need to calibrate at startup, automatic monitoring. Specification: Item Type: Air Quality Meter Model: PTH-9E Material: ABS Type: Portable Measurement Object: CO, CO2, temperature and humidity CO Measurement Range: 0-500 ppm (±5% or ±10ppm) Carbon Dioxide Measurement Range: 400~5000 ppm (±5% or ±50ppm) Temperature Measurement Range: 0 ℃-50 ℃ (±1.5 ℃) / 32 ℉-122 ℉ (±2.7 ℉) Humidity Measurement Range: 20%-80% RH (±5% RH) Power Supply: built in Li-ion Cylindrical battery (3.7V 2000mAh) Input: DC(5V-24V) Light Indicating Sound Alarm: Green: 0-100PPM, good level Yellow: 101-150PPM, normal Red: above 151-500PPM, adverse level, sound alarm Item Size: 98 x 90 x 40 mm / 3.86 x 3.54 x 1.57 inch Item Weight: 201g / 7.09oz . Package List: 1 x Air Quality Detector 1 x Type C Cable 1 x User Manual