OWC 8.0GB (4.0GB x 2pcs) or 16GB (8GB x 2pcs) PC3-10600 DDR3 1333MHz SO-DIMM 204 Pin CL9 SO-DIMM Memory Upgrade Kit for 2011 MacBookPro 13″/15″ & 17″/these rams are compatible with with iMac 21.5″ & 27″ Models Mid 2010 and 2011 series.
Warranty: Memory comes with Lifetime warranty.