The MiniDrive is a unique "short" microSD adapter that allows anyone to quickly and easily increase the available storage space in a modern laptop through use of the computer's standard SD card reader. With this adapter, you can take an inexpensive 64GB or 200GB microSD card and add "plug-in-and-forget" storage space to your MacBook. When the MiniDrive is placed into the computer it is discretely hidden. The MiniDrive can be removed by pulling a plastic tab that can be folded away when not in-use. TheMiniDrive Original is 19.5mm long and is our most universal model. It will NOT fit flush however in the MacBook RETINA 13'' (sticks out by 3.5mm) nor MacBook RETINA 15" produced after October 22, 2013 (sticks out by 1.5mm), older versions of this computer are fine. Please see our other product offerings upto 14mm long for these computers for. Please also email us if you have any questions about compatibility.