PORTABLE DRIVE FOR EASY FILE STORAGE This compact USB drive fits easily in a pocket or bag, so it's simple to back up, store, and transport files. SanDisk Secure Access software allows you to create a password protected folder on your drive to store your private data. Move Huge Files Fast Work as fast as you need to with premium performance and huge capacities in a portable yet tough and reliable USB flash drive. Blazing-fast performance lets you transfer a full-length 4K movie to the drive in less than 15 seconds1 or 1000 photos in less than 25 seconds Grab and go without worrying about everyday wear and tear thanks to an elegant yet durable aluminum metal casing About real capacity 128GB = approximately 114GB-120GB 256GB = approximately 224GB-240GB 512GB = approximately 480GB-500GB 1TB = approximately 880GB-980GB *1GB=1,000,000,000 bytes. Actual user storage less. Based on internal testing; performance may be lower depending on drive capacity, host device, OS and application. 1MB=1,000,000 bytes Based on internal testing using Telcordia stress part testing. Speeds Of Up To 400MB/s Product name: SanDisk Extreme Speed USB 3.2 Flash Disk Capacity: 256GB，128GB，64GB Performance: Read speed up to 400MB/s， (256GB): Write speed up to 240MB/s (128GB): Write speed up to 180MB/s (64GB): Write speed up to 100MB/s Generation: USB 3.1. Compatibility:USB 3.1 (backward compatible with USB 3.0 and USB 2.0). Dimensions: 60.3mm*18.0mm*7.4mm Working temperature: 0°to 45° Storage temperature: -10°to 70°