G.SKILL Ripjaws V Series 8GB (2 x 4GB) 288-Pin DDR4 SDRAM DDR4 2133 (PC4 17000) Desktop Memory Model F4-2133C15D-8GVR Desktop Memory - Newegg.com
A-Tech 8GB (2x4GB) RAM for MSI (Micro Star) Aegis X | DDR4 2666MHz PC4-21300 Non ECC SO-DIMM 1.2V - Laptop & Notebook Memory Upgrade Kit at Amazon.com
Original Apple Mac Mini 2018 RAM 8GB Kit (2x4) DDR4-2666 SODIMM SO-DIMM | eBay
Amazon.com: Patriot Memory Viper 4 Blackout Series DDR4 8GB (2 x 4GB) 3200MHz Kit : Arts, Crafts & Sewing
Amazon.com: OWC 8GB (2 x 4GB) PC19200 DDR4 2400MHz SO-DIMMs Memory Compatible with Mac Mini (Late 2018), 27" and 21.5" iMac (Mid 2017), and Compatible PCs (OWC2400DDR4S08P) : Everything Else