-Model: 2X2000mAh Heating about 2-3 hours <br />-Battery Voltage: 3.7V Li-ion Battery<br />-Battery Capacity: 2000mAh<br />-Keep Warming Time:About 3-5 Hour. <br />-Heating Area:Hand Back and Plam Fingers Duplex Heat Warm <br />-Outer Materials:EVA enviro