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 About capacity: 256GB=approximately 220GB-240GB 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 Package included: 1 X USB flash drive