Astra-Gear 8GB(1x8GB) 2666MHz DDR4 Unbuffered Non-ECC U-DIMM Upgrade for Desktop Memory Ram 1.2V CL19 260-Pin(AHD19S8G26S) at Amazon.com
ADATA 8GB DDR4 2666 (PC4-21300) SODIMM 260-Pin Laptop Memory Module Single Rank 2666MHz 8GB at Amazon.com
Crucial RAM 8GB DDR4 3200MHz CL22 (or 2933MHz or 2666MHz) Laptop Memory CT8G4SFRA32A at Amazon.com
AITC 16GB (2 x 8GB) Laptop Memory Module Upgrade DDR4 2666MHz SO-DIMM, Notebook Ram Module at Amazon.com
Crucial Memory Bundle with 16GB (2 x 8GB) DDR4 2666MHz SODIMM Upgrade kit CT2K8G4SFS8266 Compatible with iMac Retina 5K 27-inch 2019 (iMac19,1) and Mac Mini 2018 (Macmini8,1) at Amazon.com
Amazon.com: Corsair Vengeance SODIMM 32GB (1x32GB) DDR4 2666 C18 1.2V for Intel 9th & 10th Gen Systems, Black : Electronics