Arch Memory 4 GB (1 x 4 GB) 204-Pin DDR3 So-dimm for Apple iMac 27-inch 3.2 GHz Intel Core i3 (Mid 2010) RAM Arch Memory is a Registered Trademark of Arch Computer, LLC 1 x 4GB DDR3-1333 PC3-10600S 204-Pin Sodimm 1.5 volts Dual Rank (2Rx8) Lifetime Replacement Warranty Included