Like a humidor, this case maintains stable climate conditions. The newly designed air vent can be adjusted to allow airflow from the outside or to keep the case hermetically sealed. When the air vent is closed, the rubber seal protects your reeds from changing outside conditions. Using the included sponge you can add water to raise the humidity. With one glance at the hygrometer, you can make good decisions about how to care for your reeds and keep the humidity under your control. The acrylic glass can be cleaned easily with a cloth.