Product review (5 stars): Another part of the Air-O-Swiss humidifier
This is another replacement part for the Air-O-Swiss humidifier system. It is essential to have this component installed properly, or the humidifier simply will not work. The part has to be soaked in water 24 hours before using it, and you can refill it with granules that you can buy separately, to save money.

This part should be changed at least every six months, or every season when you use just the humidifier. I highly recommend this part, which is relatively inexpensive, and ships quickly from Amazon.