Adamanta 16GB (2x8GB) Memory Upgrade Compatible for 2017 Apple iMac 27"/21.5" Retina 5K/4K or Non-Retina Display DDR4 2400MHz PC4-19200 SODIMM 1Rx8 CL17 1.2v Single Rank RAM DRAM at Amazon.com
The New 2017 iMac: Notes & Tidbits on RAM- The Mac Observer
Install memory in an iMac - Apple Support (CA)
Amazon.com: Apple iMac MNE92LL/A 27 Inch, 3.4 GHz Intel Core i5, 8GB RAM, 1TB Fusion Drive, Silver (Renewed), Mac OS : Electronics
How to Install Memory iMac 27-inch 5K (RAM Crucial 16GB) - YouTube
iMac 2017 RAM update, running smoothly on 3200MHz DDR4, higher than 2400MHz Recommendation : r/mac