3pcs MQ-7 Carbon Monoxide CO Gas Sensor Module Analog and Digital Output RobotDyn for Arduino - products that work with official for Arduino boards Electronic parts : Amazon.co.uk: DIY & Tools
Interface the MQ7 carbon mono-oxide(CO) Gas Sensor with Arduino - ElectroVigyan
Smoke Detector using Arduino and Smoke Sensor | IoTDunia
Carbon Monoxide gas sensor module for Arduino MQ-7 :: Sensors :: Hobby Electronics :: Cricklewood Electronics
1PCS MQ-7 MQ7 Carbon Monoxide CO Gas Sensor Module For Arduino Mega2560 | eBay
Create Your Own CO Detector
How to Use MQ7 Gas Sensors Whith Arduino+Android App : 5 Steps - Instructables