PEN HUMIDIFIERS FOR HUMIDORS. These pen humidifiers are made out of resin and help keep the perfect relative humidity in your cigar humidor. They are gold tone and fit inside most humidors. Each pen humidifier comes with a 3M stick-on magnet and stick-on metal strip for mounting the cigar humidifier in your humidor. The humidifiers are 6.3 inches long, .67 wide and .75 height.