The product(SR-908DSZ) is a smart carbon monoxide and combustible gas combo detector with voice prompt, insert  the voice chip, microprocessor control, supports displaying of the gas concentration. This product is used to  detect both the toxic carbon monoxide gas and combustible gas (such as liquefied petroleum gas, natural  gas, CH4(methane), etc). When trigger the detector, it will alarm with build-in siren. This detector adopts  catalytic combustion method sensor and electrochemical sensor which is stable and reliable

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