16GB Apple iMac 2017 21.5" Non-Retina RAM Upgrade iMac18,1
How To Upgrade RAM in a Mac | Macworld
Memory Upgrades for 2017 iMac 27-Inch
How to Upgrade RAM on MacBook Pro, iMac & More | AVG
512GB 4X128GB NEMIX RAM Memory for Apple iMac Pro 27-inch Late 2017
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
How to upgrade RAM in the (Mid 2017) 5K iMac and save up to ~$900 [Video] - 9to5Mac