Size: 32 x 20 x 22mm / 1.25 x 0.78 x 0.86"The main chip: MQ-4 gas sensing probeOperating voltage: DC 5VPower (current): 150mADO Output: 0.1V/5VAO Output: 0.1~0.3VIndication of the signal outputDual signal output (analog output, and TTL level output)TTL output signal is low. (When low output signal light, and can be connected directly to the microcontroller)0 ~ 5V analog output voltage, the higher