STORAGE CAPACITY: 256 GB nominal storage capacity. Actual storage capacity shown by device's OS may be less than indicated on product label due to different measurement standards. Available storage capacity is higher than 230 GB DUAL PORT DESIGN: Thumb drive memory stick makes it easy to transfer data between phones, tablets, and computers EFFICIENT PERFORMANCE: Portable USB flash drive with default exFAT format offers lower power consumption, reliable performance and broad device compatibility.(Incompatible with lighting port) SPEED DISCLAIMER: Read and write speeds are based on internal tests conducted under controlled conditions. Actual read/write speeds may vary depending on devices used, transfer file size, types, and other factors PREMIUM CONSTRUCTION: Metal exterior casing with rotating open/close design and hanging hole for convenient storage