["MG811 CO2 gas sensor from the Octopus series, basic version with PCB mounting holes and connections like the other components in the series. The higher the CO2 concentration, the lower the output voltage. User can easily read the CO2 value after consulting our coding patterns. The CO2 sensor is made of industrial grade, which is highly allergic to CO2 and anti-interferential to alcohol and CO", "Operating voltage: 3.7 - 5V DC", "Connection type: G-GND, V-VCC, 5-pin signal", "Dimensions: 31 x 48mm", "Net weight: 9.6g"]