16GB KIT 2X 8GB Apple iMac 2.7GHz 21.5" Late 2013 2.93GHz 27" Late 2012 2.9GHz 21.5" Late 2013 3.1GHz 21.5" Late 2013 3.1GHz 21.5" Late 2012 3.2GHz 27" Late 2012 3.2GHz 27" Late 2013 1600 RAM Memory 16GB KIT (2 x 8GB) SO-DIMM DDR3 NON-ECC PC3-12800 1600MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For Apple iMac Series. (See Compatibility List Below)