HealthMate ® Battery Pack 4000mAh for Active Heat Knee & Back Wrap Can be used as a normal USB battery bank. 4,000mAh 4 Bar LED Battery Status Indicator Output: 5V, 1.2A Input: 5V micro-USB LED Flashlight Recharge time: 4 hours WARNING: This product can expose you to chemicals including LEAD, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.