ALMOCN MQ4 MQ-4 Methane Gas Sensor Natural Carbon CO Methand Detector Module for Arduino Raspberry Pi ESP8266 MQ4 5V DC (MQ-4) Pack of 5 : Amazon.co.uk: Business, Industry & Science
Methane Gas Sensors: All You Need to Know | GDS Corp
Methane Gas Detection | Methane Detectors | Methane Gas Alarms