Ecotechnics Evolution Digital CO2 Controller Analyser RegulatorThe Evolution Co2 Controller comes in two parts, available here together with a Regulator. Evolution Digital Carbon Dioxide Controller This Controller is the most advanced of it's kind and has more features and functionality than any other product on the market. It can be used either with or with ought the Evolution Carbon Dioxide Sensor and can be interfaced to an external thermo hygro stat ( Evolution Temperature Controller recommended) providing a