This is an Arduino hydrogen gas sensor. It has high sensitivity to Hydrogen (H2) and less sensitivity to alcohol, LPG,cooking fumes . Hydrogen gas is highly flammable and will burn in air at a very wide range of concentrations
The sensitivity is able to be adjusted by the potentiometer. The output is proportional to the density of gas. You can use analog reading to read the data from this sensor.
To ease the difficulty of using this sensor, a Gravity Interface is adapted to allow plug&play. The Arduino IO expansion shield is the best match for this senor connecting to your Arduino microcontroller.