... Detecting Instruments Supplier in China, Most Competitive price and ISO9001:2000, MA Certificate Main Technical Specification(1) Various types of ... Energy source of power supply. (3)It features in simple operation and portability. (4)It can detect ... different toxic gases in the air including CO,CO2,H2O,H2S,NH3, ... at any time. Colorimetric Gas Detection Tubes (20 In Pack)