Product Show Speed Read Rate Up to 25MB/S Write Rate Up to 15MB/S Speed is depend on host device, interface, usage conditions and the type of your device. Feature Support System Windows/Mac OSX/Android/Linux/IOS8.0 and aboved Support iphone iPhone5/5s/5c/6/6plus/6S/6S plus/7/7Plus/8/X Support ipad ipad pro/ipad 4/Ipad Air and etc, Support Android Android 5.5 and aboved(with OTG Function) About use Plug and Play (software needed from store) Interface type USB2.0/Lightning. Body Glass material/Aluminum alloy Safety Dustproof,Shockproof,Touch ID With iphone Weight 18g Size 28.4*35.65*6.2mm Operating Temperature (0 C to 60 C) Storage Temperature (-20 C to 85 C) About capacity 8GB Approximately6.9 GB-7.3 GB 16GB Approximately14 GB-15 GB 32GB Approximately28 GB-30 GB 64GB Approximately56 GB-60 GB 128GB Approximately110 GB-124 GB 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.