TechGrow T‑2 Pro CO2 Controller (7A) is an environmental controller that regulates CO2, temperature, and humidity in grow rooms. It provides a dedicated CO2 relay and a variable‑speed fan output rated 7 A for ventilation control. The unit measures and displays CO2, RH, and air temperature using TechGrow’s S‑4 sensor (not included), which also enables automatic day/night switching via its built‑in light sensor. CO2 setpoints are adjustable from 300–2,000 ppm, or up to 10,000 ppm when paired with the 10k S‑4 version. Additional features include pulse dosing, adjustable hysteresis, an automatic dosing counter with 7‑day log, and calibration for CO2 and temperature. Power input is 100–240 V, and the controller’s listed size is 21 × 24 × 10 cm with 1.55 kg weight.