New in open box Features: 57% acrylic, 25% merino, 8% polyester, 7% nylon, 2% rubber, 1% spandex Waterproof YKK zipper pocket to secure battery 3 heating setting Sizing: L/XL = Men 9-12 or Women 10+ S/M = Men 5-8 or Women 6.5-9.5 Features: One CSA or CETL charger + USB charging cable Two super thin, light weight and curved design battery to better to fit the leg Battery 5V/2400mAh (built-in 3.7V/2400mAh, li-polymer cell) 4 to 6 hours battery charging time when empty One-year warranty on battery 4 level light indicator displaying battery level Anti-bacterial treatment Control with your cell phone or control directly on the sock battery The instruction manual is included on the APP