661-4673 Apple iMac 20" 2.66GHz Core 2 Duo Video Card, ATi Radeon HD 2400XT Apple iMac A1224 ATI HD 2400 XT GDDR3 Video Card 661-4673, 661-4663, 661-4440 Apple iMac A1224 ATI HD 2400 XT GDDR3 Video Card 661-4673, 661-4663, 661-4440