030-8-0006 K30 10,000ppm CO2 Sensor | CO2Meter.com
Adafruit SCD-30 - NDIR CO2 Temperature and Humidity Sensor [STEMMA QT / Qwiic] : ID 4867 : $58.95 : Adafruit Industries, Unique & fun DIY electronics and kits
8 environmental sensors for Raspberry Pi that you can buy on Ebay — Hatari Labs
100,000ppm MH-Z16 NDIR CO2 Sensor with I2C/UART 5V/3.3V Interface for Arduino/Raspeberry Pi | Sandbox Electronics
Raspberry Pi Temperature and CO2 Monitor - Hackster.io
Adafruit SCD-40 - True CO2, Temperature and Humidity Sensor [STEMMA QT / Qwiic] : ID 5187 : $44.95 : Adafruit Industries, Unique & fun DIY electronics and kits
CO2-Logger development kit - Measure CO2 levels with your Raspberry Pi
Monitoring my home's air quality (CO2, PM2.5, Temp/Humidity) with AirGradient's DIY sensor | Jeff Geerling
Adafruit SCD-30 - NDIR CO2 Temperature and Humidity Sensor [STEMMA QT / Qwiic] : ID 4867 : $58.95 : Adafruit Industries, Unique & fun DIY electronics and kits