Sony MS-EX4G 4GB Memory Stick Pro-HG Duo Type --- Memory Stick Interface (serial/4-bit parallel/8-bit parallel) Write Speed --- 40Mbps minimum (when optimized with compliant host devices) (4-bit parallel); 120Mbps minimum (when optimized with compliant host devices) (8-bit parallel) Transfer Speed (Parallel Transfer) --- 480Mbps (60MB/sec) in Parallel Transfer (Theoretical maximum speed)