Apple Computer , iMac 20-inch 2.66 GHz Core 2 Duo (E8135), iMac 21.5-inch 2.5/2.7 GHz Core i5 (i5-2400S, i5-2500S), iMac 21.5-inch 2.8 GHz Core I7 (i7-2600S), Order Number, MC978LL/A, MC309LL/A, MC812LL/A, BTO/CTO, Model Number, A1224, A1311, Part Name, Optical Drive, Manufacture Part Number, AD-5960, GA32N, GA31N, EMC Number, EMC 2266, EMC 2428, EEE Code, DFF0, DFF2, DG96, DNRQ, DNRR, Compatible Apple Computer, iMac (21.5-inch, Late 2011), iMac (21.5-inch, Mid 2011), ,
Order you product here: 661-5933 Optical Drive to iMac 21.5 inch A1224 A1311 2011 MC978LL/A, MC309LL/A, MC812LL/A, BTO/CTO (AD-5960, GA32N, GA31N), 661-5933
source http://info.applepartsellers.com/661-5933-optical-drive-to-imac-21-5-inch-a1224-a1311-2011-mc978ll-a-mc309ll-a-mc812ll-a-bto-cto-ad-5960-ga32n-ga31n