Sony XQD High-speed memory card | XQD G Series Memory Card is the best performing XQD card for 4K users. Its outstanding reading speed of 400MB/s and writing speed of 350MB/s* enhances the capabilities of high-speed burst shooting with DSLR cameras. A Sony unique Speed-Degradation Avoiding Function enables stable recording with 4K video cameras.* Based on Sony internal testing. Transfer speed may vary and depend on host device.