I have an Early 2008 MacPro and it seems that this card can be plugged in it (that is why I bough it).
The real problem was when I've tried to plug it into my Mac so I hope my review will help those who encounter the same problem as I had.
1/ I have found a website which explain where I can plug my AirPort Extreme card in my Mac but it was for older card with only 2 connector (I'm sorry I can't add the link but Amazon removed it). 2/ I've follow the instruction until I discover that I have 3 antennas in the MacPro (hidden under the mother board) and 3 connector on the AirPort Extreme card and this is what I've done after: I have connected the antenna 1 to the ch0 connector, the antenna 2 to the ch1 connector and the antenna 3 to the ch2 connector.
Bluetooth is still working fine (I have a keyboard, a mouse and a headphone that work without problem). I mention that because I found websites where people said that the antenna 1 must be plugged to Bluetooth module. My Bluetooth card is connected to the BT antenna and it works perfectly. My AirPort Extreme card was immediately found by Mac (OS X.9.2) and works perfectly with my WiFi network (the WiFi rooter is not the same floor than my computer - at least 30m).
I hope this can help those who, like me, buy this card without having a user guide and wants to connect their device properly. I don't know if it is plug the way it must but it works. ;-)
Exactly as stated ( even came with mounting screws ) Very prompt service. NOTE : If you have never fitted one of these before, search internet for instructions / assistance as it can be tricky to get the antenna connections onto the card. Be careful not to damage the connectors and make sure they are in the correct order.
I bought this to replace an unreliable network card, and have been very happy. This card is reliable, holds a connection well, and has decent performance. Also, if you like tooling around with FreeBSD, then this card will work great.