About capacity display in computer :

16GB=approximately 14GB-15GB

32GB=approximately 28GB-30GB

64GB=approximately 56GB-60GB

128GB=approximately 110GB-118GB

Flash memory vendors are using decimal arithmetic: 1MB = 1000KB, 1G = 1000MB calculated, but the operating system is using binary arithmetic: 1MB = 1024KB, 1GB = 1024MB. So there are some differences between display capacity and nominal capacity of flash memory products. However, this is allowed to exist. Please do not doubt his authenticity. This is calculation difference between manufacturer and our PC; please Google 'Memory card capacity' to get more information.

About writing and reading speed :

16 - 32gb class 10 SDHC;

64gb 128gb class 10 SDXC

Withretail package, without usb card reader

1x memory card

1 x SD adapter

1x retail package