The Hotronic Custom Boot Heater is a portable foot warmer designed for winter sports enthusiasts. Its rechargeable batteries make it convenient for use on the go, and the red color adds a stylish touch. Made by Hotronic, this foot warmer is perfect for keeping your feet warm during skiing, snowboarding, and snowshoeing activities. Its custom design ensures a snug fit in your boots, providing reliable heat when you need it most. With its compact size and easy-to-use features, this Hotronic Custom Boot Heater is a must-have accessory for cold weather adventures.

I did plug in to test batteries.