Top quality usb flash drive pen drive 4GB 8GB 16GB 32GB 64GB waterproof Metal Key pendrive Card Memory Stick Drives u disk Please read carefully before placing an order 1=4G,2=8G,3=16G,4=32G,5=64G 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 . Maximun Read Rate: 20Mb/S Interface USB 2.0 Excellent USB Memory stick in excellent condition About capacity: 4GB=approximately 3.6GB-3.8GB 8GB=approximately 7.4GB-7.6GB 16GB=approximately 14.4GB-14.8GB 32GB=approximately 28.5GB-30GB 64GB=approximately 58.5GB-60GB 128GB=approximately 110GB-120GB Vendors are using Flash memory decimal arithmetic: 1 MB = 1000KB, 1G = 1000 MB Calculated, operating system with binary arithmetic: 1 MB = 1024KB, 1 GB = 1024 MB;So there are some differences between display capacity and nominal capacity of flash memory products.