Features Specification: Item Type: 18650 Battery Holder Case Material: PCB Purpose: This module can be used to power for Raspberry Pi and sensors at the same time. The output current of this model can reach 2A, which can power many control boards. Charging Port: Micro USB Charging Current: 0.5A Output Voltage: 5~8V Battery Type: 18650 x 4 (self-provided)  Package List: 1 x Battery Box 1 x Connecting Line Note: This product does not contain 18650 batteries. When installing, pay attention to the positive and negative poles of the battery, do not reverse the connection, please follow the +‑ direction on the PCB, and do not follow the positive and negative directions on the battery holder Package List