OWC 16GB (2 x 8GB) PC21300 DDR4 2666MHz SO-DIMMs Memory Compatible with Mac Mini 2018, iMac 2019 and up, and Compatible PCs (OWC2666DDR4S16P) at Amazon.com
Crucial 16GB DDR4-2666 SODIMM Memory for Mac | CT16G4S266M | Crucial.com
16GB DDR4 2666 2667 MHz PC4-21300 Memory RAM for APPLE MAC MINI Late 2018 A1993 | eBay
2020 2019 5K 27 inch IMAC 64GB 32GB 16GB 8GB DDR4 2666 2667 apple all-in-
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