These paks provide an inexpensive way to remove small amounts of moisture from a system. Desiccant is contained between two wire mesh sheets so that chamber air can be circulated through the desiccant. The paks are designed to be stacked together so that multiple layers of desiccant can be added to the catalyst. No more than three paks are recommended for each fan box in order to maintain proper chamber air flow. Desiccant can be rejuvenated following the same procedure and schedule that is used for the catalyst.