Kingston Technology 8GB Kit (2x4 GB Modules) 1333MHz DDR3 SODIMM Notebook Memory for Select Apple iMac's and Macbook Pro's KTA-MB1333K2/8G 8 GB kit including two 4 GB modules of 1333MHz DDR3 Memory Specifically designed and tested for compatibility 204-Pin unbuffered SODIMM From the industry leader in PC memory Backed by a lifetime warranty and free technical support