The Kuidada C307 Electric Hand Warmer in black is a reusable and adjustable heat device perfect for outdoor activities such as camping, hiking, hunting, and backpacking. With a material of plastic and an activated temperature of 50°C, this compact hand warmer provides warmth for up to 7 hours. Weighing 4.4 oz, it is easy to carry and store, making it a convenient addition to your outdoor gear collection.