<p><b>About capacity:</b></p><p></p><p>128GB=approximately 116GB-120GB</p><p></p><p>256GB=approximately 228GB-236GB</p><p></p><p>512GB=approximately 462GB-490GB</p><p></p><p>This is calculation difference between manufacturer and our PC, please Google 'Memory card capacity' to get more information.</p><p><br></p><p></p><p></p><p><b>Warm Tips:</b></p><p></p><p><b>1.</b>Our Store offers 100% genuine memory card with 1 years warranty.</p><p></p><p><b>2.</b>Please use quaity card reader to verify all memory card  on PC.</p><p></p><p><b>3.</b>Please don't use cheap card reader to test memory  card, speed of memory  card will be reduced by low quality card reader.</p><p></p><p><b>4.</b>Memory  card speed is greatly affected by card reader, adapter, USB port etc. Low quality device will 100% slow down card speed.</p><p></p><p><b>5.</b>Up to 40MB/s read speed; write speed lower. Based on internal testing; performance may be lower depending on host device, interface, usage conditions and other factors. </p><p></p><p><b>6.</b>If you have any questions about this card, please contact us directly through Amazon. thank you for coming<b>!</b></p>