Digital Quick Thermometer (to double check incubator thermometers) accurate to +/- 0.2 *F Much more accurate than normal incubator thermometers. Stick through hole in side of incubator and check temp in about 60 seconds, to see how far off your incubator thermometer is and better judge where 99.5 degrees F is at on your regular thermometer. Can not be used as a stand alone thermometer inside the incubator, use only to check accuracy of other thermometers. Comes with batteries, ready to use. We stick the tip through a small hole we have made in an air plug in the side of Sportsman incubator, for hands free use.