Features: DIY Powerbank Box with no soldering design allows easy assembly using 1x21700 batteries (not included), featuring double output and intelligent charging protections for safe mobile device charging. Equipped with LCD power display, USB C input port, and separate battery slot monitoring, this 21700 battery charger case automatically stops charging when full while ensuring compactly portability. Ideal for enthusiasts and outdoor adventurers who prioritize customizable power solution, requiring reliable charging for phones during travel, camping, or daily commutes. Perfect for emergency backups at remote job sites, week end getaways, or crowded event where double device charging and real time battery status monitoring is essential. Crafted with durability ABS materials, this 21700 battery powerbank box combines ruggedness with plugs and play simple for seamlessly on travel energy management. Specifications: Component:Plastic Size:Approx.8.5x2.75x4.8cm/3.35x1.08x1.89inch 4Option Color Applicable model:21700 Battery Tip: 21700 batteries is not included in the package, you need to purchase separately. Please pay attention to the direction of the positive and negative poles.Do not close the cover until test it is finished, it can not open again if closed. Package Includes: 1pc Charger Case(without Battery) note: Please allow 1-2cm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual item color.