iMac 2019 Ram upgrade.

Your system needs PC4-21300 DDR4 2666 MHz

iMac memory specifications

I generally recommend buying RAM either directly from the supplier or from a major store. Buying from Amazon or eBay can be very iffy!

As an example here’s the Crucial web site for the RAM your system needs Crucial 16GB DDR4-2400 SODIMM. I was looking just the other week for some SODIMM’s for a customer and Crucial was out of stock then as well. I would make a call to Crucial, don’t forget Crucial is a memory manufacture. The demand for these SODIMM modules is stripping supply.

So is your source real or fake? Do they really have them in stock? So be careful!