4000 mAh rechargeable battery. It doubles as a backup battery for your USB devices. 2 heat settings to adjust, plenty of heat to keep your hands warm in colder weather. Battery and heat indicator lights will show you quickly the selected heat settings, rechargeable hand warmers offer you an instant double-sided heat in just senconds. With one-button easy to use system, it heats up fast with the punch of a button Soft and Comfy surface allows you to easily wrap around to enjoy the warmth from across the palm down to the thumb. Lightweight and sleek design can easily fit in your pocket or stay fixed in your glove. Package includes: 1*fflannelette, 1* charging cable, 1*rope. Perfect for outdoor sports and events, indoor offices, transit, indoor gaming and Raynauds arthritis sufferers for heat therapy needs.