I got this for my MacBook Air 11' as it doesn't have an internal SD card reader like the larger models. This card reader hardly ever works properly. It most often cannot even identify the card, and when it does, it sometimes stops reading the card mid-way through the import. Waste of money, I do not recommend it.
Bought this card reader a year back and mainly uses it to extract photos from my CF card. It hasn't been reliable most of the time, sometimes the reader does not want to read the data from the card, other times it just stops halfway while the photos are being imported. And recently after just about a year of use, the card reader fails totally! While this card reader is beautiful, it just isn't worth the trouble, get something else!