The Therm-ic C-Pack Set 1300 is a perfect choice for anyone who gets cold feet on the mountain. This set includes two battery packs and a USB charger. Three different heat settings are controlled by a single button on the battery pack to deliver up to 13 hours of warmth on the mountain. The USB charger has your battery packs fully juiced in 5-7 hours. Therm-ic Boot Heaters are not only used to improve your comfort, but to boost your performance as well. Every hour you are out in the cold your balance and muscle dexterity decreases. By having warmer feet, not only will you be more comfortable you will be skiing better too. Single Control Button, USB Charger Included, Compatible with all Ski Boots and Insoles, A Must Have for Skiers with Diabetes or Raynaud's, Does Not Include Heating Elements or Cambrelle Covers, Battery Heated: Yes, Model Year: 2020, Product ID: 544902, Model Number: T41-0101-100, GTIN: 3661267096099