Features 4 in 1 Smart Tester: Equipped with buzzer alarm, this monitor can be used to test CO2 concentration, temperature, humidity and sound level. Simple in Operation: Supports 2.4G WIFI, the 4 in 1 CO2 monitor also enables easy operation as well as data check on the mobile phone APP. Reliable Detection: Wide in test range and high in accuracy, the sound meter has 11in LED display, 6 decibel indicators and 3 CO2 indicators. Has 2000mAh Battery: Built in 2000mAh battery can work continuously under maximum brightness, which can be fully charged within 1.5 hours. Broader Application: Can be widely applied in bedroom, kitchen, office, school, car, cellar, planting room, camping, party and other places. Specification: Item Type: CO2 Monitor CO2 Indicator: Green: 400~1000ppm Orange: 1001~2000ppm Red: 2001~5000ppm Decibel Indicator: One Green Light: <55db Two Green Lights: 55~65db One Orange Lamp: 65~75db Two Orange Lights: 75~85db One Red Light: 85~95db Two Red Lights: >95dB Function: Integrated decibel meter for the detection of CO2 concentration, temperature, humidity. Atmospheric Pressure: 86-106Kpa Sampling Time: 1.5 Seconds Decibel Measurement Range: 30~130dB Decibel Accuracy: ± 1.5dB Noise Detection Method: dB condenser microphone. Noise Concentration Unit: dB Frequency Range: 50Hz~8.5kHz Resolution: 0.1dB Detection Temperature: - 10℃ ~ +50℃ Temperature Accuracy: ± 1.0℃ (0℃ ~ 40℃) Temperature Unit: Celsius Storage Temperature: - 10℃ ~ 60℃ Detection Humidity: 20%~85% Working Environment and Storage Humidity: 10%~80% Humidity Accuracy: ± 5% CO2 Detection Method: Infrared NDIR. CO2 Concentration Unit: PPM CO2 Detection Range: 400-5000 ppm CO2 Alarm Value: 1000ppm Setting: Supports manual setting of 800ppm-2000ppm CO2 alarm threshold. Alarm: CO2 alarm on and off function. If you doesn't like the alarm, you can turn it off. Battery: 1 x 18650 2000mAh, shipped with built in battery.  Package List:1 x CO2 Monitor 1 x USB Cable2 x User Manual2 x Screw2 x Wall Plug1 x Installation Sticker Package List 1 x CO2 Monitor 1 x USB Cable 2 x User Manual 2 x Screw 2 x Wall Plug 1 x Installation Sticker