FEATURES: - Perfect for outdoor activities like snowmobile, motorcycling, mountain climbing, camping, hiking, skiing, Fishing, Hunting or office routine and business use during fall and winter months. - Rechargeable. You can use your own power bank to charge the vest, make sure to use 5V / 2.1A USB Port. NOTE: No Battery Included. The USB plug is compatible with most power bank in the market. - Help promote blood circulation and relief of muscle pain. Great gift for parents and family members. - Built-in thermal protection module. Once it is overheat, it would stop until the heat return to the standard temperature, so it is 100% safe to use. - Instant Heating. Provides instant heat for the body in one minute during cold weather helping you to avoid cold and chills. SPECIFICATIONS: Material: Polyester Color: black, blue,gray