OLOy DDR4 RAM 16GB (1x16GB) 2400 MHz CL17 1.2V 260-Pin Laptop Gaming SODIMM for Intel (MD4S162417IZSC) at Amazon.com
Amazon.com: OWC 32GB (2 x 16GB) PC19200 DDR4 2400MHz SO-DIMMs Memory Compatible with Mac Mini (Late 2018), 27" and 21.5" iMac (Mid 2017), and Compatible PCs (OWC2400DDR4S32P) : Everything Else
Corsair Vengeance LPX 16GB (2x8GB) DDR4 DRAM 3000MHz C15 Desktop Memory Kit - Black (CMK16GX4M2B3000C15) at Amazon.com