Digital control board delivers precision CO2 control. Maximize your CO2 production while minimizing CO2 consumption. Controls any CO2 equipment that is operated by 120 Volt power. Durable powder coated, steel enclosure will stand up to the toughest conditions. Adds CO2 only during daylight period using the controllers integrated photocell. 50 parts per million (PPM) deadband/hysteresis built into set point. Memory retains controllers setting even when the power is off. 15 Amps maximum/120 Volt/60 Hz. Patent No. D657,748.