Made with a lightweight PVA material, the 6667 Wet Evaporative Cooling Vest provides immediate cooling relief to the core area. Lightweight construction is designed with breathable, mesh-panel siding, allowing a more comfortable wear compared to other wet vests. Front zipper provides a quick way to remove. 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 wring excess water out. It remains cool up to 4 hours. Use vest 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. This wet vest is ideal for those working in hot environments including construction, roofing and landscaping. It can also be used to reduce the risk of heat stress while mountain biking, motorcycling, hiking and more. Machine-wash as needed and hang dry for longer life.