How to Upgrade iMac Hard Drive or SSD 2012-2022: EveryMac.com
27 inch iMac with Retina 5k Display 2019 3.7GHz i5 1TB SSD 32GB RAM | Refurbished | Techable
27 inch iMac with Retina 5k Display 2019 3.7GHz i5 4TB SSD 8GB RAM | Refurbished | Techable
NEMIX RAM 64GB Memory Upgrade Kit (2x32GB) SODIMM DDR4 2666MHz PC4-21300 Compatible for Apple iMac Mid 2020 (iMac20,1 / 20,2) / Mid 2019 (iMac19,1) 27-inch w/Retina 5K Display, Late 2018 Mac Mini 8,1 at Amazon.com
Timetec 8GB Compatible for Apple DDR4 2666MHz for Mid 2020 iMac (20,1 / 20,2) / Mid 2019 iMac (19,1) 27-inch w/Retina 5K Display, Late 2018 Mac Mini (8,1) PC4-21333 / PC4-21300 SODIMM MAC RAM Upgrade at Amazon.com
DIY Bundle - 1TB OWC 6G SSD and HDD Kit for 21.5-Inch iMac
iMac 5k 27" Full Upgrade (CPU, RAM, SSD and M.2 NVMe) - Step by Step Time-lapse. - YouTube
Timetec 32GB Compatible for Apple DDR4 2666MHz for Mid 2020 iMac (20,1 / 20,2) / Mid 2019 iMac (19,1) 27-inch w/Retina 5K Display, Late 2018 Mac Mini (8,1) PC4-21333 / PC4-21300 SODIMM MAC RAM Upgrade at Amazon.com
Timetec 64GB KIT(4x16GB) Compatible for Apple DDR4 2666MHz for Mid 2020 iMac (20,1 / 20,2) / Mid 2019 iMac (19,1) 27-inch w/Retina 5K Display PC4-21333 / PC4-21300 CL19 SODIMM Memory MAC RAM Upgrade
OWC DIY Drive Upgrade/Install Kits for Apple iMac Models
crucial memory bundle with 32gb (2 x 16gb) ddr4 2666mhz sodimm upgrade kit ct2k16g4sfd8266 compatible with imac retina 5k 27-inch 2019 (imac19,1) and mac mini 2018 (macmini8,1) - Newegg.com