OWC 8GB PC14900 DDR3 1866MHz SO-DIMM Memory Compatible with 2015 (Late) iMac 27" w/Retina 5K Models and Compatible PCs (OWC1867DDR3S8GB) at Amazon .com
Kimtigo DDR4 2666 8G Laptop Dram 2666MHz (PC4-21300) CL19 (Compatible with 2400MHz or 2133MHz) 1.2V Notebook 1Rx8 Single Rank 260 Pin SODIMM Laptop PC Computer Memory RAM(8GB) at Amazon.com
Kingston KCP316SD8/8 8gb 1600mhz Sodimm Mem at Amazon.com
Mushkin Essentials – DDR3 Laptop DRAM – 8GB Memory Single SODIMM – DDR3L-1600MHz (PC3L-12800) CL-11 – 204-pin 1.35LV Notebook RAM – Low-Voltage – (992038) at Amazon.com