It can be used in coal gas, natural gas, boiler, industrial furnace, automatic electronic gas burner, etc WELCOME TO SIHON ELECTRONICS CO LTDWHAT YOU SEE IS WHAT YOU GET!!!favourable(If you buy ten ones ,we will send you other one for free, also twenty for two amd so on ) 1.Usage: Mainly used in coal gas, natural gas, boiler, industrial furnace, automatic electronic gas burner, etc 2. ...