About capacity:
What is the real capacity?
Flash memory vendors are using decimal arithmetic:1MB = 1000KB,1G = 1000MB 
calculated, the operating system using binary arithmetic:1MB = 1024KB,1GB = 1024MB;
so there are some differences between display capacity and nominal capacity of flash memory product.
4GB=approximately 3.5GB-3.7GB
8GB=approximately 7.4GB-7.8GB
16GB=approximately 14GB-15GB
32GB=approximately 28GB-30GB
64GB=approximately 58GB-59GB
This is calculation difference between manufacturer and our PC, please Google 'Memory card capacity' to get more information.

Features:
Supports hot plug & play, High speed USB 2.0 port
No physical drive required 
Plug-and-play; no external power supply required, USB bus-powered
Support all current computer systems
speeds vary depending on types of file being transferred and computer configuration.
Read Rate: 12-18 Mb/S    Write Rate:4-6 Mb/S
Interface USB 2.0
Excellent USB Memory stick in excellent condition