Finally an accurate digital hygrometer with the look and feel of a classic analog hygrometer! Cigar Oasis and Western Humidor have combined the best of both worlds with this classic looking round hygrometer that contains the same sensor, circuitry and calibration as the Caliber IV digital hygrometer. Caliber digital hygrometers are known for their reliable accuracy, slim profile design and no hassle operation. The Caliber 4R Digital Round Hygrometer displays humidity and temperature, can record maximum and minimum readings and may be set to display in either Celsius or Fahrenheit. Diameter: 2.25 inches.