etc. CGD01B: Analogs circle, 50-10000PPM measurement ranges, powered by 3 * AAA battery(not included), 5 minutes automatic shutdown. CGD02B: Digital concentration display and analogs bar, 50-50000PPM/0-100%LEL measurement ranges, powered by built-in 18650 battery(included), 10 minutes automatic shutdown. Specifications: Name: Combustible Gases Detector Material: plastics Model: CGD01B, CGD02B (optional) Sampling method: Diffuse Response speed: Starting in 2 seconds Calibration mode: 30 seconds automatic calibration Alarm mode: sound, backlight, screen display Test Gases (partial list): methane, ethanol, gasoline, propane, benzene, oxirane, n-hexane, butane, ethylene, carbon monoxide, acetone, ethane, etc. Preheat time: 30 seconds Operating temperature: 0-50°C Working humidity: 0-70%RH Storage environment: -10~50°C (5%-95%RH) CGD01B: Battery: 3 * AAA Alkaline Battery (not included) Display: analogs circle Test ranges: 50-10000PPM Auto power off: 5 minutes Working current: 120mA CGD02B: Battery: 1 * 3.7V, 2000mAh 18650 lithium battery (included) Display: digital LCD concentration display and analogs bar Test ranges: 50-50000PPM/0-100.0%LEL Test flowrate: 1L/min Gases resolution ratio: 1%LEL/1PPM Charging interface: USB Type-C USB charging: 5V, 1A Measurement resolution: ＜±5%LEL, ＜±500PPM Auto power off: 10 minutes Working current: 185mA Hose length: 285mm / 11.22in Item size: 165 * 53 * 34mm / 6.50 * 2.09 * 1.34in Package size: 190 * 65 * 45mm / 7.48 * 2.56 * 1.77in Package weight: CGD01B: 220g / 7.76ounce CGD02B: 370g / 13.05ounce Packing List: 1 * Combustible Gases Detector 1 * Guideline