2X DDR3 4GB Ram PC3 12800 1600MHz 1.5V Desktop PC Memory 240Pins System High Compatible for Intel(4 GB) - Walmart.com
OWC 8 GB (2 X 4GB) ram PC8500 DDR3 1066MHz sodimm 204-pin Memory Upgrade Kit, (OWC8566DDR3S8GP), Compatible with MacBook Pro, MacBook, Mac Mini and iMac at Amazon.com
DDR3 4GB Memory Ram+Cooling Vest PC3-12800 1.5V 1600Mhz 240 Pin Desktop Memory DIMM for Desktop AMD Motherboard - Walmart.com