OWC 32GB (2 x 16GB) PC21300 DDR4 2666MHz SO-DIMMs Memory, Compatible with Mac Mini 2018, iMac 2019 and up, and Compatible PCs, (OWC2666DDR4S32P) at Amazon.com
32GB DDR4 3200MHz DIMM PC4-25600 UDIMM Non-ECC CL22 2Rx8 1.2V 288-Pin Desktop PC RAM Memory Module M378A4G43AB2-CWE at Amazon.com
Apple Memory Module 32GB DDR4 2666MHz SO-DIMMS (2x16GB) - Apple