This analogueue gas sensor has a small heating element with an electronic-chemical sensor. It is suitable for indoor use. You can adjust the sensitivity (threshold setting) using a potentiometer mounted on the bottom of the sensor module. https://elecena.pl/product/28015623/joy-it-gas-sensor-with-adjustable-sensitivity 2025-03-12 https://elecena.pl/product/28015623/joy-it-gas-sensor-with-adjustable-sensitivity 2025-05-22 https://elecena.pl/product/28015623/joy-it-gas-sensor-with-adjustable-sensitivity 2025-07-18 https://elecena.pl/product/28015623/joy-it-gas-sensor-with-adjustable-sensitivity 2025-09-17