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
HP S1 Single RAM 8GB DDR4 2666MHz CL19 Laptop Memory - 7EH98AA#ABC at Amazon.com
Crucial 8GB DDR4-2666 PC4-21300 CL19 Single Channel Memory Module CT8G4SFRA266 - Micro Center
Lenovo 8GB DDR4 2666MHz UDIMM Memory-US | Lenovo US