I have a MacBook Pro, and after reading many reviews bought this product. The transfer speed is great, when it works. The trouble I have is every time I insert a card into the reader, I get that grey screen that tells me to hold down the power button to restart my computer, in about 6 different languages. I restart, after loosing progress on the things this "grey screen of death" as interrupted, then I am able to read the card just fine. This is a horrible manufacture default. I'd give this product 1/2 a star if i could and if i could take a screen shot when that grey screen appears, i would but this freezes my computer.
I don't even know if what I received was a Delkin model as there is no marking on my reader at all. Bottom line: Do not buy this product.