This part is a kind of semiconductor called MQ-4.

Function of this product has GAS SENSOR.

Manufacturers : HANWEI ELETRONICS

Image and pinout :

Some of the text within the PDF file :

HANWEI ELECTRONICS MQ-4 www.hwsensor.com TECHNICAL DATA MQ-4 GAS SENSOR FEATURES * High sensitivity to CH4，Natural gas. * Small sensitivity to alcohol, smoke. * Fast response . * Stable and long life * Simple drive circuit APPLICATION They are used in gas leakage detecting equipments in family and industry, are suitable for detecting of CH4,Natural gas.LNG, avoid the noise of alcohol and cooking fumes and cigarette smoke. SPECIFICATIONS A. Standard work condition Symbol Vc VH PL RH Parameter name Circuit voltage Heating voltage Load resistance Heater resistance Technical condition 5V±0.1 5V±0.1 20KΩ 33Ω±5% Remarks AC OR DC ACOR DC Room Tem PH Heating consumption B. Environment condition less than 750mw Symbol Tao Parameter name Using Tem Technical condition -10 [ ... ]

MQ-4 PDF Datasheet Download