Crucial 16GB Single DDR4 2666 MT/s (PC4-21300) DR X8 SODIMM 260-Pin Memory - CT16G4SFD8266 at Amazon.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
Crucial - DDR4-16 GB - DIMM 288-Pin Very Low Profile - 2666 MHz/ PC4-21300 - CL19-1.2 V - unbuffered - ECC, CT16G4XFD8266 at Amazon.com