The MiniDrive is an adaptor that allows anyone to add additional storage space to a laptop through use of a microSD card. It slips into the MacBook's SD card slot to enable a semi-permanent, on-board, secondary storage drive.  All Adapter at TheMiniDrive support any capacity MicroSD card so you can add 64GB or 128GB to your MacBook and when a 256GB MicroSD get released the current MiniDrive will be compatible.