Crucial RAM 8GB DDR4 3200MHz CL22 (or 2933MHz or 2666MHz) Laptop Memory CT8G4SFRA32A 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