1. Contains 128GB ultra-high speed memory card, reads 99MB/s, writes 90MB/s. 2. The aluminum alloy shape is closely integrated with your MacBook. 3. Quick and easy access is only required with a fingertip or a card similar to a bank card. 4. Automatically back up your data with your MacBook. 5. Support Macbook Pro Retina 15 inch (end of 2013 - after), models are: MJLU2 / MJLT2 / MJLQ2 / MGXC2 / MGXA2 / ME294 / ME292.