Features: This 18650 battery holder lets you build a powerbank instantly by simply inserting 8 cells and connecting the terminals. Crafted with high strength impacts resistant plastic, the compactly powerbank box integrates built in overcharge/over discharge/short circuit protections and clear charging indicators for reliability portability power management. Ideal for enthusiasts, electronics hobbyists, and outdoor adventurers seeking a customizable, user friendly power solution without technical expertise. Perfect for emergencies charging during travel, camping trips, or daily commutes, securely powering smartphones, tablets, and small devices through its USB output port. The modulars design with lock compartments ensures stable battery alignment while maintaining pocket sized portability, requiring only initial full charging activation before first use for optimal performances. Specifications: Component:Plastic Color:Black,White; Size:Approx.170x80x23mm/6.69x3.15x0.91inch Suitable for 8x18650 Battery Tips: 18650 batteries are not included in the package, you need to purchase separately. Please pay attention to the direction of the positive and negatives poles. Do not close the cover untill the test it is finished, it can not open again if closed. After installing the battery, please fully charging it and activate it before outputting. Package Includes: 1pc Battery Case note: Please allow 1-3cm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual item color.