The Chill-Its 6685 Dry Evaporative Cooling Vest offers immediate dry cooling relief that lasts up to three days. The exclusive dry evaporative technology keeps the wearer completely dry and comfortable as opposed to other cooling vests on the market that require soaking. Constructed with high-visibility industrial grade quality nylon to perform in the toughest conditions. Designed with front zipper closure, and the mesh side panels provide additional ventilation and stretch for a comfortable fit. This lightweight cooling vest is machine washable and can be reused over and over. To activate, simply fill the vest with 13 oz to 20 oz water for immediate and long-lasting cooling relief. Not to be worn underneath thick layers of clothing, this vest needs airflow in order to activate and for the evaporation process to take place. Do not clean the inside reservoir. Cooling material is treated with an antimicrobial that inhibits mold growth on the product.Note: This is a non-returnable item.