Dri-Z-Air Unit - Use this unit to protect against damage caused by moisture. It is easy to use. Is odorless, non-flammable, and will eliminate those musty smells while it removes excess moisture. Helps prevent condensation and mold from forming on windows and surrounding surfaces. Great for bedrooms, bathrooms, boats, RVs, garages, basements and storage areas. One Dri-Z-Air unit is recommended for every 10 foot x 10 foot space. For example, use one Dri-Z-Air unit in a small bedroom or three Dri-Z-Air units in a 25 foot motor home. The placement of the units is important. In a 25 foot motor home, place a Dri-Z-Air unit in the rear, middle and front. Comes with one bag of crystals for the unit. (For refill bags of crystals see our part #7015300.) Black in color. 1 unit per package.