Product review (4 stars): Aprilaire #4655 Humidistat works well on my GeneralAIr Humidifier
The Aprilaire #4655 Humidistat has kept the humidity -in house of 2300 Sq. Ft.- in the 33 percent range, when set at 35. No monitoring or tinkering necessary. My classical guitar appreciates the constant humidity, tuning degradation is uniform for all strings.