Specifications NameBack SupportControllable temperature40 ±5℃ 60℃ ±5℃ Power supply8000mAh power bank not included Working time4 6hrsMaterialWorsted Nylon Carbon fiberSizeS M L XLColorBlackWeight220gSuit forAdult Men and WomenSizeLength cm Suggested Height m Suggested Weight kg S M401 5 1 7535 65L XL461 75 1 965 95Features HEALTH CARE Far infrared wave light help promote blood circulation relief pain of muscle enhance metabolism and improve immunity QUICK HEATING Built in 3 secured heating sheets quick heating in seconds with 5V battery LASTING WARM Working time is about 4 6 hours with 8000mAh power bank not include powered CONTROLLABLE 3 available heating settings can be adjusted 40°C 60°C for different temperature of environment SUPERIOR MATERIAL Worsted vest smooth and wind protective allowing hand wash cleaning PROTECTIVEPRACTICAL Perfect gift for seniors and friends who like snowmobile skiing ice fishing and camping in winter Package Included 1 x Waistcoat Built in USB Cable