Features: 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. Do not close the cover untill the test it is finished, it can not open again if closed. Please note that the capacity of each battery must be same. Do not place the battery upside down as it will damage the motherboards. (The spring is the positive pole, and the other end is negative pole) Please place it correctly.There is no chance of secondary disassembly, and the shells cannot be disassembled again!Perfect for outdoor travel use. Specifications: Material:Plastic Color:Clear Number of batteries: 3x18650 batteries Model:YM693 Input: 5V 2A (Micro+Type-C Input) Output: 5V 2A (Double USB Output) 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.