TarDisk R15B 256 GB Flash Memory Hybrid Drive: Simplest way to increase onboard  MacBook Storage. Flush, seamless integration into SDXC port. Additional storage space is added directly to existing Hard Drive presenting the user with a single, larger, unified volume. Storage: 256GB integrated flash memory with precision UniBody Aluminum enclosure. Speed: 95MB/sec write, 90MB/sec read. Fits: 15" Retina MacBook Pro (Late 2013, Mid 2014, Early 2015+)