These are by far the best we’ve seen for the money. A lightweight, fast response electronic thermometer 5 1/2 inches long. Accurate to within 1° F (-58 - 266 °F, 2 °F at 267 - 338 °F) with a -58 - 338° F range, this pocket sized unit is well suited for on-the-spot measuring of substrate/soil temperatures. Battery included.