Android phones must have Android 4.4 or above and support OTG function. The actual read and write speed depends on the hardware and software of the connected device and your personal usage habits. Personal usage habits. The test condition of the maximum speed is based on an empty disk/USB3.0/ATTO test tool. Different hardware and software conditions. Different hardware and software conditions can lead to different test results. Capacity on the product (decimal) Windows output (binary) (1TB=1000GB, 1GB=1000MB, 1MB=1000KB) 512GB512GB476GB 1TB≈931GB 2TB≈1.82TB