Late-2015 Apple iMac with 2.8GHz Intel Core i5 Quad-core (21.5-Inch, 8GB RAM, 1TB) (Renewed)
OWC 16GB (2x8GB) ram Upgrade PC3-12800 DDR3L 1600MHz sodimm 204 Pin CL11 Memory Upgrade Kit Compatible with Late iMac, Mac Mini, and MacBook Pro Computer at Amazon.com
Apple iMac 21.5-inch A1418 Late 2015 Logic Board i5 1.6GHz 8GB Memory non-Retina | eBay
Install memory in an iMac - Apple Support
Apple iMac 21.5" Desktop - 1.6GHz Dual-Core i5 - 8GB RAM - 256GB SSD - (2015) - Silver - Best Deal in Town