4GB (2 x 2GB) DDR3 1600MHz PC3-12800 204-PIN SODIMM MEMORY RAM KIT FOR LAPTOPS | eBay
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 (8gb (1 x 8gb)) - Newegg.com
OWC 8GB PC3-12800 DDR3L 1600MHz SO-DIMM 204 Pin CL11 Memory Module Upgrade Compatible with iMac, Mac Mini, and MacBook Pro (OWC1600DDR3S8GB) at Amazon.com