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
Samsung Original 16GB, (2 x 8GB) 240-pin DIMM, DDR3 PC3-12800, Desktop Memory Module at Amazon.com