Capacity 4GB; Dimensions (LxWxH) 15mm x 11mm x 1.0mm; Weight Approx 0.25g; Working Voltage 2.7~3.6V; Speed class UHS-I (UHS: Ultra High Speed); Transfer speeds : up to 20 (MB/s), Random (read) : 500 IOPs, Random (write) : 50 IOPs; Compatibility smartphone, tablet, mobile phone;