Samsung 4GB DDR3 PC3-12800 1600MHz 204-Pin SODIMM Laptop Memory Module RAM. Model M471B5273DH0-CK0 at Amazon.com
Samsung ram Memory 4GB (1 x 4GB) DDR3 PC3-12800,1600MHz, 204 PIN, SODIMM for laptops at Amazon.com
OWC 32GB (4 x 8GB) PC12800 DDR3L 1600MHz SO-DIMMs Memory Compatible with 2011-2015 iMac Models (OWC1600DDR3S32S) at Amazon.com
OWC 16GB (2x8GB) ram Upgrade PC3-12800 DDR3L 1600MHz sodimm 204 Pin CL11 Memory Upgrade Kit Compatible with Late iMac, Mac Mini, and MacBook Pro Computer at Amazon.com