This product is used to detect smoke and combustible gases, including hydrogen, methane, and propane (LPG) gases. Features: Used to detect smoke and combustible gases, including hydrogen, methane, and propane (LPG) gases. Dual signal output. Analog (AO pin) and TTL (DO pin) level output. The TTL output signal is normally low and becomes high when gases are detected. The threshold is adjusted by the built-in potentiometer. Analog output voltage 0 ~ 5V. The higher the gas or smoke concentration, the higher the voltage. Has good sensitivity for liquefied gases, natural gases, urban gases, and smoke. Has four screw holes for mounting. Has a fast response, long service life, and reliable stability. Suitable for domestic and industrial use. Specifications: Input Voltage: DC 5V Dissipated Power (Current): 150mA Item Size: 32 * 22 * 20mm / 1.26 * 0.87 * 0.79in Package Size: 45 * 45 * 20mm / 1.77 * 1.77 * 0.79in Package Weight: 13g / 0.46ounces Note: 1. Due to the different display screen and light effect, the actual color of the item might be slightly different from the color showed on the pictures. 2. Please allow a little measuring deviation due to manual measurement.