SMALL ANALOG HYGROMETERS FOR HUMIDORS. These small analog hygrometer are made out of resin and keeps perfect relative humidity. They have a hole in the center of the back for calibration and are gold tone. It is a replacement hygrometer for ESPECIAL, AMOR 425, MIO, TRAVELER and EL MIO Humidors by Cuban Crafters. They also serve as replacement hygrometers for most humidors and fits smaller hygrometer holes. The hygrometers are 1.75 inches in diameter, the back has a diameter of 1.50 inches and from front to back are .6 inches.