SAMSUNG M471B5173QH0-YK0 SamSung 4GB 1Rx8 PC3L-12800S,1600Mhz, SODIMM-204P (MX15GARA-B6ND at Amazon.com
Samsung ram Memory Upgrade DDR3 PC3 12800, 1600MHz, 204 PIN, SODIMM for 2012 Apple MacBook Pro's, 2012 iMac's, and 2011/2012 Mac Mini's (4GB (1 x 4GB)) at Amazon.com