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
Kingston Technology 16GB Non-ECC CL11 DIMM 1600MHz DDR3 RAM (KVR16N11K2/16) - Kit of 2 at Amazon.com