The Lenz Heat Vest is very unique because of its low-profile fit that can be worn as a mid-layer or as a stand alone heated vest. We love the Lenz heated vest because of the long battery life and excellent heating performance.Lenz Heated Vest Set Includes: 2 lithium packs rcB 1800 (rechargeable) 1 global USB-charger 100 - 240 V 1 USB charging cable with charging indicator 1 heat vest 1.0 Lenz Heat Vest 1.0 Features: breathable vest with 2 heating elements in the kidney and back area maximum comfort as well as mobility thanks to 4-way stretch and highly elastic seams fits under clothing thanks to minimum volume disperses moisture perfectly and dries out again quickly wind and water repellent and non-abrasive (no peeling effect) zip protection system fleece insert in collar area, inner pocket machine washable at 30°C light lithium packs fit all models of lenz heat socks, heat vest, heat bandage and LED system attach lithium pack to the vest via press studs heat can be regulated via 3 settings on the lithium pack heat can be continuously regulated remotely via smartphone (Bluetooth smart ready) heat development for up to 20 hours short charging time flexible plastic case Lenz Heated Vest Materials: outer material: 84 % nylon, 16 % spandex inner material: 100 % polyester Lenz Heat Vest 1.0 for Women w/ rcB 1800 Battery Packs