I got back from the Apple store a short time ago with my Mac Pro Airport Extreme card. It was a bit hard to instal in that the two wires were hard to work with in such a small space and the wires being so short. It's hard to get them to "plug" onto the card. I found it easier to plug the card into the socket first and fasten the two screws then secure the wires. Works flawlessly.
Inside the box is the card, warranty and two screws in a packet. There is also a CD for the AEBS but it is not needed if your AEBS is already configured in your network.