DDR4 2400MHz PC4-19200 for Apple iMac 21.5" 18,1 & 18,2
Amazon.com: 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 (OWC2400DDR4S32P) : Everything Else
Apple Memory Module 16GB DDR4 2400MHz SO-DIMM (2x8GB) - Apple
8GB Memory Upgrade for 2017 iMac 27-Inch
Amazon.com: OWC 64GB (4 x 16GB) PC19200 DDR4 2400MHz SO-DIMMs Memory Compatible with 27" iMac (Mid 2017), and Compatible PCs (OWC2400DDR4S64S) : Everything Else
Apple 32GB (2 x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 Memory Upgrade for Late 2015-2017 iMac 27 inch with Retina 5K Display at Amazon.com
64GB (4X 16GB) DDR4 2400MHz PC4-19200 SO-DIMM RAM Memory Upgrade for 2017 iMac 27 inch with 5K Retina Display (PARTS-QUICK) - Walmart.com
Crucial 8GB DDR4-2400 SODIMM Memory for Mac | CT8G4S24AM | Crucial.com
16GB PC4-19200 RAM for Apple iMac Mid 2017 - 27 Inch Retina 5K MNE92LL/A - MNE92xx/
Crucial Ballistix Sport LT 2400 MHz DDR4 Laptop iMac Memory Kit 8GB (4G x 2) | eBay
8GB iMac Memory for 27-inch Retina - 2019 to Current - Models 19.1 20.1 20.2 | Ramjet.com
DDR4 2400MHz PC4-19200 for Apple iMac 2017 27-inch w/Retina 5K iMac 18
Apple Memory Module 16GB DDR4 2400MHz SO-DIMM (2x8GB) - Apple
Timetec 16GB Compatible for Apple 2017 iMac (27-inch w/Retina 5K, 21.5-inch w/Retina