Keep Safe-- The gas detector is mainly used to detect natural gas (main components: methane), LPG (main components: propane, butane) and urban coal gas (alkane, olefin, arenas). When the combustible gas leak exceeds the standard, the gas detector will sound a slow, accelerated or hurried, continuous 85dB sound alarm. It cannot detect toxic gases such as carbon monoxide. LED Digital Display and Audible Warning-- The gas detector indicator shows 0 under normal conditions. If a flammable gas leak is detected, numbers 1-9 and A may be displayed on the screen. The alarm sounds and flashes red once the concentration is above 3% LEL. The alarm will be in different alarm states depending on the concentration of flammable gas. Durability and Energy Saving-- Standard European plug design, plug-and-play, no converter required, makes it extremely easy and convenient to install. This detector is anti-mold, anti-pest and anti-corrosion. Flame retardant ABS plastic, easy to clean. Uses less than 2 watts of electricity, significant energy saving. Widely used for restaurant, kitchen, hospital, hotel, oil factory, garage, gas station and so on. Test Method-- Press and hold the lighter switch located at the gas inlet of the methane detector, then deflate slowly (do not turn it on during deflation) . When the concentration reaches the standard, the alarm will sound until the volume of the gas in the environment falls below the alarm point. Precautions: System warm-up time is approximately 2-3 minutes. During this period, the gas test will not work. After-sales Guarantee-- This gas alarm is safe and durable. It uses high quality sensors, semiconductor heating and SMT chip technology.