Now you can watch Mother Natures Magic as eggs hatch before your eyes. This scientifically designed styrofoam incubator weighs 4 pounds, is 18 x 18 x 7-1/2, draws 25 watts, 110 volt A.C. The THERMAL AIR FLOW MODEL (without fan) is the most economical. Thermal action of the heated air flows out of the exhaust vents in the top of the incubator and draws fresh air in through the bottom vent. This action also helps in the drying of the chicks after they hatch. Without a fan you may notice the temperature fluctuate with the different sizes of eggs you hatch, or within the climate of the room. The CIRCULATED AIR FLOW MODEL (with fan) makes incubating eggs more reliable. The increased air flow permits the incubator to be operated at one temperature for all sizes of eggs and climate conditions. It holds a more uniform temperature. Incubators should be in a room where the temperature doesn't change much, and located in an area where there aren't fans, air conditioners, or heat vents blowing directly on the incubator. This helps the incubator stay at a more uniform temperature inside. Approximate egg capacity without turner: 200 Quail, 90 Pheasant or Chukar, 70 Chicken, 40 Turkey or Duck. Also included is the automated egg turner which will hold up top 42 poultry or small duck sized eggs! Hatch poultry, gamebirds, waterfowl, tropicals and, without the turner installed, even reptiles.Temperature range is from room temperature to about 104 degrees F, thermostatically controlled by you.