TechNiche, Evaporative Cooling KewlShirt Tank Top, Powered by HyperKewl PLUS, designed to be worn directly against the skin. Simply soak in water for 1-2 minutes for 5-10 hours of effective cooling. Machine Washable up to 104F/40C. Features: Traditional tank top styling, made with comfortable Spandex HyperKewl fabric inner and waterproof nylon liner Designed to be worn against the skin for maximum cooling effect, with ventilation vents built into back and front panels Best worn underneath a breathable sports jersey or on its own Can provide 5-10 hours of cooling relief Lightweight, easy to activate, and durable Sizes: XS, S, M, L, XL, 2XL, 3XL, Custom Color: Black/Silver, Black/Teal, Black/Yellow