Datasheet : https://www.pololu.com/file/0J311/MQ4.pdf_x000D_ _x000D_ Character_x000D_ * Good sensitivity to Combustible gas in wide range _x000D_ * High sensitivity to Natural gas _x000D_ * Long life and low cost _x000D_ * Simple drive circuit _x000D_ _x000D_ Application_x000D_ * Domestic gas leakage detector _x000D_ * Industrial Combustible gas detector _x000D_ * Portable gas detector