XIKAR PuroTemp round digital hygrometer has been designed for long term accuracy and minimal maintenance. They accurately display the relative humidity and temperature in your humidor. The size is a standard 1.75" so that it fits in the same hole as nearly every analog hygrometer that usually comes with a humidor. You can now upgrade your old analog to a digital with the XIKAR Adjustable Round Digital Hygrometer. Features: Accurate to +/- 2% at 70% humidity. Reads humidity in the range of 20% to 95%. Registers temperature in Fahrenheit and Celsius.