NVidia GeForce 6800GT 6800 GT 256MB AGP Video Card - will it works with MAC

Hi, I am trying to buy the NVIDIA upgrade graphics card for my mac. I found this card on Ebay, NVidia GeForce 6800GT 6800 GT 256MB AGP Video Card - but the seller doesn't know if it will work with MAC. How should I find out whether it will work? Is there any diference between these cards for PC and MAC? Thanks a lot, Mastro

PowerMac g5, Dual 2ghz Mac OS X (10.4.8)