A-Tech 16GB (2x8GB) RAM for Apple MacBook Pro (Early/Late 2011), iMac (Mid 2010 27 inch 4-Core, Mid 2011 21.5/27 inch), Mac Mini (Mid 2011) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Kit at Amazon.com
Kingston Value (KVR16N11S8/4) RAM 4GB 1600MHz PC3-12800 DDR3 Non-ECC CL11 DIMM SR x8 Desktop Memory at Amazon.com
Geil Pristine 4 GB DDR3 1600 MHz Desktop RAM
Samsung ram Memory 4GB (1 x 4GB) DDR3 PC3-12800,1600MHz, 204 PIN, SODIMM for laptops at Amazon.com
Hynix DDR3 4GB 4096MB PC3-8500u 1066MHz Lodimm Lo-dimm Desktop Memory DRAM 240pin at Amazon.com