Digital Monitor High Speed Micro SD Card Reader Function Charger: You can check the battery level on the digital display at any time when you need it. Black Reader Box has a micro SD card reader when you hook up the device to you computer with a foldable USB cord from charger. Protected against overcharging, short circuit, and electronic shock, over discharge, over-temperature, over current, over voltage. The charger box is easy to carry and doesn't occupy the backpack spac