A single Concrobium Moisture Grabbers pouch is effective for spaces up to 350 cubic feet. This product is ideal for use in small, confined spaces including closets, bathrooms, cabinets, pantries, storage bins, safes, cars, trucks Concrobium Moisture Grabbers use a formula of Zeolites and Super Absorbent Polymers (SAPs) to draw moisture from the environment and keep spaces dry. Zeolites are minerals that can be readily dehydrated and rehydrated (great for absorbing water). SAPs are materials that can absorb and retain extremely large amounts of liquid relative to their mass (used most commonly in diaper technology). The combination of these materials attract and absorb moisture better and faster, at lower relative humidity (RH) levels, to protect your spaces and valuables from moisture damage.