... . FeaturesEnvironment friendly electrochemical technology sensor with high accuracy and long term reliabilityFive years sensor life, low cost,best ... -interference ability optional 2 relay outputs: warn & switch control Range 0-400ppm within the range (and extensible ... , beautiful and easy, convenient installation and use SpecificationsCO sensor: electrochemical air sensorsRange: 0~100ppm, or others(0 ...