Features: Experience the convenience of this DIY 4x18650 Battery Case, a versatile solution for charging your devices on travel. Crafted with durable materials, this battery case ensures long lasting use and reliable power for your devices. Designed for gadget enthusiasts, this battery case allows you to easily assemble and customize your own portable charger by installing 4x18650 batteries. Monitors your battery capacity, voltage, and current in real time with the LCD digital display, ensuring you're always aware of your power levels. 18650 batteries are not included in the package, you need to purchase separately. Can only use the 18650 battery of which positive electrode is flat top. Note:Do not reverse the positive and negative poles; Specifications: Material:Plastic Color:Black,Red,Blue,Green;(Optional) Number of batteries: 4x18650 batteries Size:Approx.103x80x24mm/4.06x3.15x0.94in Double USB Output:5V/2.4A (Most) Input:5V/2.1AType-C/Micro USB Package Includes: 1x Power Bank Case (Battery not include) note: Please allow 1-2cm errors due to manual measurement,please make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.