MQ4 gas sensor based gas sensor, can be very sensitive detection of methane into the air, natural gas and other gases.
But ethanol and low sensitivity to smoke.
Combined with Arduino expansion board using special sensors, can produce methane fire, gas leak alarm and other related works.

• Comes with uppercase letters A, show an analog sensor.
• High quality interface. Immersion Gold process and improve quality.
• 3MM diameter distance between the mounting holes is a multiple of 5mm.

Comes with uppercase letters A, show an analog sensor.Haweier