Can you use Plugable USB 2.0 Multi-Card Reader to backup your save for Mac?

[AzureMagic]

I know I ask a lot of dumb newbie questions but I've decided to back up my X save file on my Mac so I ordered a Plugable USB 2.0 Multi-Card Reader. off Amazon because it was cheap.

The problem is is that I take out my SD Card and place it in the card reader, plug it to my MacBook Pro, and nothing shows up. Nothing happens. And it's not like it's incompatible with Mac because it very clearly says that it should work with Mac, and my computer up to date.

If there's a problem with the reader can someone recommend me something that does work for MacBook Pro? My Mac is version is 10.9.2 if that matters.