Carbon Dioxide IR (CO2) Infrared 0–5.00% Vol. Sensor
Infrared Carbon Dioxide CO2 C4 sensor in 4 or 7 series standard size with integrated analogue (standard 0.4-2.0V) transmitter, 0-5000ppm, 0-2% vol.; 0-5% vol.; 0-100% vol
Amazon.com: DFRobot Gravity: Analog Infrared CO2 Sensor for Arduino (400~5000 ppm) : Electronics
1pcs MH-Z19 NDIR CO2 Sensor Module Infrared co2 Sensor 0-5000ppm for CO2 Monitor Carbon Dioxide Sensor MH-Z19B with Lines: Amazon.com: Industrial & Scientific
Arduino Nano with NDIR CO2 Sensor code queries - Sensors - Arduino Forum
Industrial Scientific 17155304-U Ventis PRO 5 Infrared Carbon Dioxide / Hydrocarbon (CO2/HC) Sensor, 4 Series - Durawear.com