The Harvest-Master Climate Controller is extremely advanced. There is nothing else like it on the market. The scientist-developed factory settings make growing plants simple. Take the guesswork out of growing your plants! 

Just set the Growth Cycle you want: Vegetative, Fast Flowering or Full Flowering. This climate controller knows what it takes to achieve the optimum results.

Automatically sets the days long with nights short to get maximum growth, then short days with long nights to bring on flowering. An awesome tool to shorten the growth cycle! Grow things faster! Get 1, 2, or 4 extra crops per year.

Along with temperature and humidity sensors, there are 8 additional outputs (each needs relay switch) to control Lights, Exhaust fans, CO2, Cooling/Air Conditioner, Heating, Humidifier or Dehumidifier, etc.

More info (PDF format)