Ergodyne - EGO12693 6667 Wet Evaporative Cooling Vest is made with a lightweight PVA material for immediate cooling relief to the core area. Lightweight construction is designed with breathable, mesh-panel siding, allowing more comfortable wear compared to other wet vests that can be heavy. Front zipper offers an easy on/off, customized fit. For best results, wear this body-cooling vest over a T-shirt and not covered by other clothing. To activate the cooling feature, run under water and then wring excess water out. It remains cool up to 4 hours. Vest works best in dry environments. Simply reactivate when it becomes stiff by running under water again. PVA material is super-evaporative, keeping you cool and comfortable for hours. It is ideal for those working in hot environments including construction, roofing and landscaping. Vest can also be used to reduce the risk of heat stress while gardening, hiking, playing sports and more. Machine-wash as needed and hang dry for longer life.