The mold is and simple. You only need to unscrew the inner bracket, put it into the battery, put it back into the inner bracket, and tighten the bottom cover to remove it repeatedly and replace the battery infinitely. It's very convenient to use.Features:Made of fine quality material, safe to use.Easy to install and use.18650 battery charger DIY box for all cellphones with a micro USB socket.You are required to assemble them yourself, and the battery is not included.Plug and play, output using the USB port, plug the data cable to achieve portable, ready to charge.Different kinds of colors for your choice.Specifications:Item type: USB  CoverMaterial: Aluminum alloyColor: Golden, silvery, black, red, blue, pink, green, purple, dark blue, rose golden(optional)Cell type: 18650 batteryInput: 5V/1A(MAX)Output: 5V/0.1-1APackage weight: 30g / 1.05ouncesPackage size: 100 * 30 * 30mm / 3.93 * 1.18 * 1.18inchesPackage list:1 * USB Cover a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a