The Chill-Its® Premium Phase Change Cooling Vest is made to house phase change cooling packs (not included) to keep workers cooler, safer and more productive. The phase change cooling material maintains a 64° F (18° C) temperature for up to 4 hours when activated. The vest is made of a modacrylic cotton blend FR 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. The cooling vest comes in two sizes ranging from S/M (32in - 40in / 81cm - 102cm) to L/XL (40in - 52in / 102cm - 132cm). FLAME RESISTANT – Vest made with modacrylic cotton blend FR fabric FLEXIBLE FIT – Adjustable hook and loop closures on both shoulders and waist MORE COOLING POWER – Extended vest surface area enhances cooling power REFLECTIVE ACCENTS – Designed for more visibility on busy streets or job sites CONVENIENT STORAGE – Two elastic pen loops on chest AVAILABLE IN 2 SIZES: S/M and L/XL TESTED & APPROVED – Fabric meets ASTM F1506 performance requirements (ATPV rating of 7.1 cal/cm2); Classified to NFPA 70E (CAT1) Cooling packs sold separately and feature: IMMEDIATE & LONG-LASTING COOLING RELIEF – Packs maintain constant 64°F (18°C) for up to 4 hours QUICK RECHARGE – Packs recharge in a little as 10 minutes HONEYCOMB DESIGN – Patented honeycomb ice pack design eliminates stiffness WEIGHT WITH PACKS: S/M - 6lbs / 2.7kg, L/XL - 9lbs / 4kg Vest only - No cooling packs included Chill-Its® Premium FR Phase Change Cooling Vest - Vest Only 6225