Samsung 4GB DDR3 PC3-12800 1600MHz 204-Pin SODIMM Laptop Memory Module RAM. Model M471B5273DH0-CK0 at Amazon.com
Silicon Power Hynix IC Compatible for Apple DDR3 DDR3L 16GB (2 x 8GB) RAM 1600MHz (PC3 12800) 204 pin CL11 1.35V Non ECC Unbuffered SODIMM Laptop Notebook Memory RAM Module Upgrade at Amazon.com