Apple iMac 27" - Core i5 10th gen, 8GB 2666 DDR4, 256GB SSD, MacOS | GCOM IT PLACE
OWC 256GB 2666 MHz DDR4 LRDIMM Memory Upgrade Kit
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 - Newegg.com
Timetec 32GB KIT(2x16GB) Compatible for Apple DDR4 2666MHz / 2667MHz for Mid 2020 iMac (20,1/20,2) / Mid 2019 iMac (19,1) 27-inch w/Retina 5K, Late 2018 Mac Mini (8,1) PC4-21333 /PC4-21300 MAC RAM at Amazon.com
Refurbished: Apple Mid 2020 iMac with 3.3 GHz Core i5 (I5-10600) (27 inch Retina 5K, 32GB RAM, 512GB SSD) MXWU2LL/A A2115 32GB DDR4 512 GB - Newegg.com
16GB Memory for Apple iMac Retina 5K, 27-inch (2020) DDR4 2666 MHz PC4-21300 RAM | eBay
Timetec 32GB KIT(2x16GB) Compatible for Apple 2017 iMac 27-inch w/Retina 5K Display, 2017 iMac 21.5-inch w/Retina 4K or Non-Retina DDR4 2400MHz PC4-19200 CL17 Sodimm RAM Upgrade (32GB KIT(2x16GB)) - Walmart.com
Amazon.com: V-Color 32GB(2x16GB) 2666MHz ddr4 Compatible for iMac Retina 5K, 27-inch, 2019 and iMac Retina 5K, 27-inch, 2020 Non ecc SODIMM Mac Memory Ram Upgrade pc4-21300 CL19 260-pin 1.2V (TN416G26D819K-VC) : Everything