<p>QAs:</p> <p>1. Why the capacity is only 119GB shows in the computer?</p> <p>Answer: because of the different algorithms, Mathematically 1GB = 1000MB = 1000x1000KB = 1000x1000x1000 bytes, all the manufactor use this way to mark the capacity, that means 128GB = 128x1000x1000x1000 bytes. But in computer algorithm, 128.000,000,000 bytes = 128000000000 / 1024 /1024 /1024 =119.2GB, so most of the 128GB micro sd cards will be real 119GB showed in the computer, and different nand flash from different manafactor will also cause differences in capacity, usually it will be 116-120GB real capacity shows in the computer.</p> <p>2. Why it doesn't work for my device?</p> <p>Answer: The default format of the microSD card with capacity 64GB/128GB/256GB are newest exFAT, some early devices are not very compatible with exFAT format, you can format it to FAT32 in the computer and then try again in your device.</p>