"Caution *LARGE* size hygrometer"
Be advised, the diameter of this hygrometer is 3 inches. Most humidors supply a SMALL (1.75") hygrometer. This may prove to be a problem if your humidor has an existing, SMALL, external hygrometer. Be sure you take into account the clearance between the lid and/or the bottom of your humidor's existing hygrometer hole. With the larger size of this hygrometer, it may overlap onto the humidor lid, or even, cause a clearance problem with the bottom of the humidor.
GarDad in Waldorf, MD February 2, 2012