Other reviewers were right about the flimsy build quality. I tore the piece of junk apart with my bare hands. If you absolutely have to have an ExpressCard with FW ports, buy anything but this.
If you can make it work, it will give you two full-size firewire ports
This card sucks. I had it for about a year, and in that time I was constantly messing with it to make my laptop recognize my external soundcard with it. Often the only way to get it working right was to plug everything in, then power cycle the sound...