The Aoyun AOY-718 Rechargeable Portable Hand Warmer 2-in-1 is a versatile and compact hand warmer designed for outdoor activities like camping, hiking, and skiing. Its 2-in-1 design allows you to use it as a hand warmer or a power bank to charge your devices. duration of 8.5-20 hours. Its small and handy size makes it easy to carry around, making it a must-have for staying warm on the go.