I built a new incubator over the weekend. It's a 120qt Igloo controlled with a Herpstat and flexwatt, with two - 12v fans to circulate the air/heat. I originall set it up with a forced air heater, but it got too hot too quick, and seemed like a waste of energy (1500w vs 70w). It has two viewing windows and interior viewing lights with an on/off switch on the outside. The thermostat is embedded in the front of the cooler for a perfect fit. It can hold 8 - 6qt egg boxes. I'm really happy with how it turned out.