NCAA Rechargeable Hand Warmer Stay warm all Season long; aluminum shell with dual-face heating Surface heats up to 104f Keeps you warm for 2-3 hours; best when kept insulated Rechargeable lithium-ion Battery charges in 2 hours; mini USB port; 5V/600M ah Input Includes insulating S and charging cord Aluminum shell with dual-face heating Heats up to 104 degrees Built-in, rechargeable lithium-ion battery Run time: 2-3 hours