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. Design features V-neck 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 again. SIZING The cooling vest comes in six different sizes ranging from medium (38in - 41in / 97cm - 104cm) to 4XL (53in - 56in / 135cm - 142cm). To find your size, wrap a tape measure around the widest part of your chest, under your arms, and completely around your torso. See size chart for more information. HOW TO ACTIVATE Simply fill the vest with 13oz - 17oz / 400ml - 500ml water for immediate and long-lasting cooling relief. No refrigeration or gels necessary! Cooling process can last up to three days depending on humidity and heat levels. High humidity levels can slow down airflow and may reduce cooling abilities. HOW TO WEAR Not to be worn underneath thick or heavy layers of clothing, this body cooling 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 anti-microbial that inhibits mold growth. Always keep cap closed to maintain vest’s effectiveness. This evaporative cooling vest is perfect for anyone in need of instant cooling relief while working or playing outside in warm temperatures where heat-related illnesses like heat cramps, heat strokes, heat exhaustion, etc. are possible. Ideal for workers in construction, carpentry, mining, landscaping or for people running, biking, doing yard work, riding a motorcycle, and more!