Fangrui Product Details Introducing The Gas Sensor Module - Enhance Your Environment With Precise Monitoring Of Co2 Levels, Essential For Maintaining Optimal Indoor Air Quality. Combining High Accuracy With Affordability Empower Your Indoor Spaces With The Sensor Module, Ensuring Long-lasting, Efficient, And Accurate Air Quality Monitoring To Promote Health And Well-being. Intelligent Adjustment Of Indoor Ventilation Systems Can Be Achieved Based On Carbon Dioxide Concentration, And Indoor Air Quality Helps To Maintain A Healthy Environment Under Low Carbon Dioxide Concentration For A Period Of Time. Reference Accuracy, Specified Range 400-2000 Ppm Power Supply Voltage Range: 2.4-5.5 V High Precision: (40 Ppm+) Digital I2c Interface Integrated Temperature And Humidity Sensors Low Power Operation To Less Than 0.4 Ma Average Value @ 5 V, 1 Measure/ 5 Minutes 1. Gnd: Power Negative Input Port 2. : Power Positive Input Port 3. Scl: I2c Clock Port 4. Sda: I2c Data Port Board Size: 13.4 X 21.6mm- Compact Yet Highly Effective, Fi Easy To Clean And Maintain