Heat exchange technology. Unlike all other coolers on the market this cooler draws warm air out of the chamber, cools the air then directs the cold air back into the chamber. The key to this very high efficiency cooler is it operates at zero pressure differential utilizing a 30 plate heat exchanger. It can drop the heat in the chamber 20 to 30 degrees or below room temperature by about 2-3 degrees. This comes with two pumps, cooler chest, heat exchanger and all required hoses and fittings.