FEATURE:

* Durable data storage: 4GB/8GB/16GB/32GB/64GB/128GB.
* USB 3.0 high-speed data transfer performance.
* Plug and play: No need drive/power supply only plug in.
* A-class chip: Can be erased repeatedly for 100,0000 times.
* Support Windows computer systems,Can not support Mac system.
*Writing speed: 10-20Mb/s , Reading speed: 40-70Mb/s. The rate of performance depends on the different operation system available and various flash adopted, so the speed maybe different.

ABOUT CAPACITY:

128MB=approximately 110MB-120MB
 4GB = approximately 3.6GB-3.9GB
8GB = approximately 7.4GB-7.8GB
16GB = approximately 14.2GB-15GB
 32GB = approximately 28GB-30GB
 64GB = approximately 58GB-60GB
128GB = approximately 110GB-120GB

This is a calculated difference between the manufacturer and your PC, please google"memory card capacity" for more information.
Your PC says 1GB = 1073741824 million bytes, where the market defines 1 GB = 1 billion bytes.
Therefore, there is a certain difference between the display capacity and the nominal capacity of flash memory products.