Module application: can be used in homes and factories of gas leakage monitoring device, suitable for liquefied petroleum gas, butane, propane, methane, smoke detection. description: input voltage: dc 5v current: 150 ma the do output: ttl digital 0 or 1 (0. 1 V or 5 v) ao output: 0. 1-0. 3 V (pollution-free), the highest concentration of voltage is 4 v or so feature: dimension(lxwxh): approx. 32X20x18mm with the do (ttl) and analog output (ao) ttl output effective signal is low level with power indicator and ttl signal output indicator sensitivity can be adjusted through the potentiometer note: to get the stable measured data, the sensor needs to be preheat about 20 seconds after it is powered. Package includes: 1x gas sensor module.