Apple iMac MC309LL/A 21.5-Inch Desktop (OLD VERSION) 2.5GHz quad-core Intel Core i5 with 6MB on-chip shared L3 cache 500GB Hard Drive 4GB 1333MHz DDR3 SDRAM, DVD SuperDrive 21.5" LED-backlit display with a widescreen 16:9 aspect ratio, AMD Radeon HD 6750M Mac OS X v10.7 Lion