The SDCFE-256G-GN4NN with Memory card, Extreme Pro, CFexpress B, 256GB, R: 1500MB/s is a Compact Flash memory card manufactured by SanDisk. It is designed for photographers and videographers who need the highest read and write speeds available. Its CFexpress B interface provides a transfer rate of 1500MB/s, allowing for fast, efficient media playback and transfer. This high performance card is perfect for storing large, high-quality video, graphics, and other high-resolution data files.