A-Tech 8GB RAM for Apple iMac 2017 (27 inch Retina 5K & 21.5 inch Retina 4K) | DDR4 2400MHz SODIMM PC4-19200 1.2V 260-Pin SO-DIMM Memory Upgrade Module at Amazon.com
32GB Memory Upgrade Kit for 21.5-inch Apple iMac 2017
Timetec 32GB KIT(2x16GB) Compatible for Apple 2017 iMac (27-inch w/Retina 5K, 21.5-inch
OWC 32GB (2 x 16GB) PC19200 DDR4 2400MHz SO-DIMMs Memory Compatible with Mac Mini (Late 2018), 27" and 21.5" iMac (Mid 2017), and Compatible PCs : Amazon.ca: Electronics
Install memory in an iMac - Apple Support
Timetec 32GB KIT(2x16GB) Compatible for Apple 2017 iMac (27-inch w/Retina 5K, 21.5-inch w/Retina 4K / Non-Retina 4K) DDR4 2400MHz PC4-19200 SODIMM MAC RAM Upgrade for iMac 18,1 / iMac 18,2 / iMac
Adamanta 16GB (1x16GB) Memory Upgrade Compatible for 2017 Apple iMac 27" Retina 5K Display DDR4 2400MHz PC4-19200 | Walmart Canada