This vest is made with a lightweight PVA material that provides immediate cooling relief to the core area. The lightweight construction is designed with breathable mesh panel siding making it more comfortable than other wet evaporative vests that can be heavy to wear. A front zipper offers an easy on/off, customized fit. To activate, simply run under water and wring out – no ice or refrigeration is needed. Machine wash as needed and hang dry for longest life, the vest will stiffen as it dries. All PVA materials dry stiff – to reactivate and soften, run underwater.