A-Tech 32GB (2x16GB) RAM for Apple iMac 2017 (27 inch Retina 5K & 21.5 inch Retina 4K) | DDR4 2400MHz SODIMM PC4-19200 2Rx8 1.2V 260-Pin SO-DIMM Memory Upgrade Kit at Amazon.com
Timetec 64GB KIT (4x16GB) Compatible for Apple 2017 iMac (27-inch w/Retina 5K Display) DDR4 2400MHz PC4-19200 1Rx8 CL17 1.2V Non-ECC Non-Parity Unbuffered SODIMM Memory MAC RAM Upgrade for iMac 18,3 at Amazon.com
2017 21.5-inch 4K iMac memory upgrade kit includes 32GB of RAM, tools to take it apart | AppleInsider
DDR4 2666MHZ PC4-21300 for Apple iMac Pro 2017 1,1
Timetec 64GB KIT (4x16GB) Compatible for Apple 2017 iMac (27-inch w/Retina 5K Display) DDR4 2400MHz PC4-19200 1Rx8 CL17 1.2V Non-ECC Non-Parity Unbuffered SODIMM Memory MAC RAM Upgrade for iMac 18,3 at Amazon.com
Timetec 8GB DDR4 2400MHz PC4-19200 Compatibel voor Apple 2017 iMac (27-inch met Retina 5K, 21,5-inch met Retina 4K/Non-Retina 4K) CL17 SODIMM Geheugen MAC RAM Upgrade voor iMac18,1/iMac18,2/iMac18,3 : Amazon.nl: Elektronica