I was skeptical when I ordered this about whether it would actually work in my PSP, especially with it having two memory card slots, that seemed a bit too good to be true, but luckily I was proved wrong.
I put an 8GB microSD card and a 2GB microSD card in the adapter, put the adapter in the PSP and formatted it through the menu on there, it took a while to do it at first, but ever since it has worked amazingly.
Every now and then it doesn't work, but that is easily solved by just taking it out and putting it back in again, and this has never happened in game.
Transferring files has to be done through the PSP if you use two microSD cards in the adapter, if you only use one then you can plug it into your computer via any other method you have at your disposal for reading microSD cards, such as a USB reader
If you have a PSP and need a high capacity memory card, this is the thing for you