Description: 1.Micro SDXC Card 2.Plug and play (no software needed) 3.Micro SDXC + TF format,High-speed read and write 4.64GB, 128GB, 256GBStorage Size 5.Applies to Cell Phones, Cameras, MP3/MP4 Player and Moredevice 6.Can be Used as Micro SD or SD Card 7.Operating Temperature -13 F to 185 F (-25 C to 85 C) 8.Storage Temperature -40 F to 185 F (-40 C to 85 C) Warm Tips ( 2.0USB reader Test Result) : 64GB/128GB/256GB-Class 10-SDXC Class10: Read speed around 15-30MB/S,Write speed around 9-12MB/S The Micro SD card speed is based on internal testing; performance may be lower depending on host device, interface, usage conditions and other factors. Micro SD card speed is greatly affected by card reader, adapter, USB port etc. Low quality device will 100% slow down card speed. HardwareFeatures: Originalhighqualityflashmemory ManufacturedinTaiwan AssembledinChina About capacity: 64GB=approximately 58GB-60GB 128GB=approximately 113GB-124GB 256GB=approximately 240GB-252GB This is calculation difference between manufacturer and our PC,just for you reference. Package included: 1 X Micro sd card 1 X Free Adapter