Kingston Technology 8GB (1x8 GB) 1333MHz DDR3 PC3 10600 204-Pin SODIMM Memory for Apple iMac KTA-MB1333/8G One 8GB Module of 1333MHZ DDR3 Memory for Apple iMac Backed by a lifetime warranty and free technical support From the industry leader in PC memory Designed and tested for compatibility in Applie iMac Intel Core i5/i7 21.5-inch (Mid 2011) and Apple iMac Intel Core i5/i7 27-inch (Mid 2011)