Apple Late 2012 21.5″ iMAC MD093LL/A. I expertly upgraded this one with an Intel i7-3770S CPU which Apple offers. Added an Apple/Samsung 512gb m.2 SSD to the socket on…

FS:Apple Late 2012 21.5″ iMac i7-3770S,GT 640M,Dual SSD 480gb2.5/Apple 512gb m.2,16gb DDR3 1600 $595

Source: [H]ardOCP – FS:Apple Late 2012 21.5″ iMac i7-3770S,GT 640M,Dual SSD 480gb2.5/Apple 512gb m.2,16gb DDR3 1600 5