The Chill-Its 6225 Premium Phase Change Cooling Vest is made to house phase change cooling packs to help keep workers cooler, safer and more productive. The phase change cooling material maintains a 64°F (18°C) temperature for up to four hours when activated. The vest is made of a modacrylic cotton blend flame-resistant fabric which meets ASTMF1506 requirements as well as classified to NFPA (CAT1). The adjustable hook-and-loop closures at the shoulders and waist provide a customized and comfortable fit. Keep your writing utensils handy with two pen slots on the right-side of the vest.