iMac Late 2015 - Mid 2017 ram and SSD upgrade
SSD & RAM Installation Videos - iMac 27-inch with Retina 5K (Late 2015 - Mid 2017)
Model ID: iMac18,3 | iMac17,1
Memory Install Video
OWC Skill Level: "Easy"
Duration: 2:19
How to Upgrade or Install a SATA Drive (SSD or HDD) in the Main Drive Bay of a 27-inch Apple iMac (2012 - 2019)
Ram memory and SSD for imac18,3 check the link below:
https://www.flexxmemory.co.uk/categories/memory/apple-mac-memory/imac/2017-imac/27-inch-imac.html