About capacity:

16GB=approximately 14GB-15GB
32GB=approximately 28GB-30GB
64GB=approximately 58GB-60GB
128GB=approximately 115GB-119GB
256GB=approximately 230GB-238GB

About speed:

★Adapter is speedless. Please use quality USB 3.0 card reader to test all memory cards by H2testw on PC. Real memory card should pass H2testw with no error.
★Micro SD memory card speed is greatly affected by many factors card reader,interface, computer condition , test software ,systems, etc.Low quality device will 100% slow down the speed.

Notice:

★Manufacturer's reserve the right, at their sole discretion, to change or modify products. Appearance and packaging design may change without prior notice.
★We are not responsible for any changes or modifications that manufacturer's make to products.