You are offerding on a Sentinel CHHC-4 environmental controller. I used it for only one 3-month-long grow, and it really worked great for controlling my heating, cooling, CO2 tank, and dehumidifier. It is cutting edge technology, and incredibly accurate. sale also includes the base unit, CO2 sensor probe, power cord, instructions, box. Please email me if you have any questions and kindly check my other sales for other nice hydroponics supplies.

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