v-Color DDR4 128GB (2 x 64GB) Hynix IC 2933MHz(PC3-23400) R-DIMM for Apple Mac Pro 2019 ECC Registered DIMM Dual Rank 2Rx4 1.2V CL21 (VHA21ASDRAG4T-CG29RD) at Amazon.com
G.Skill Flare X series DDR4 kit 16 GB: 2 x 8 GB DIMM 288-pin 3200 MHz / PC4-2560 – ASA College: Florida
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
v-Color 64GB (2 x 32GB) ECC SO-DIMM DDR4 2666MHz (PC4-21300) for microservers, workstations, Networking Platforms and Embedded Systems 2Rx8 CL19 1.2V (TES432G26D819K-VC) at Amazon.com
Team T-CREATE CLASSIC 32GB (2 x 16GB) 260-Pin DDR4 SO-DIMM DDR4 3200 (PC4 25600) Laptop Memory Model TTCCD432G3200HC22DC-S01 - Walmart.com
32GB Kit MP7N2G/A (2 x 16GB) 260-Pin DDR4 So-dimm RAM | Memory for Apple Woman Owned Small Business. Ready to Ship!
Crucial 32GB (2 x 16GB) 260-Pin DDR4 SO-DIMM DDR4 2133 (PC4 17000) Laptop Memory Model CT2K16G4SFD8213 Laptop Memory - Newegg.com