Keep it Dry odor and moisture absorbing packets combine the qualities of Bincho-Tan activated charcoal and drying Crystals to form a drying and deodorizing product. Small moisture permeable packets are perfect for use in compact and contained storage situations such as lockers, gym bags, and shoes. No liquid, no mess, no spills. Fragrance-free. lasts up to 2 months. 4-pack.