Per the specs these are DDR4 2666 and 2933 (XMP memory). The memory can be found here. Also you can find Crucial here which is the most compatible. You stated that you have 32 GB installed now (though you listed 16 GB in the system specs). But if you already have Fury HyperX memory installed from the factory, then adding more of the same type should be compatible. The memory should have a part number on the sticker.
My Area-51 desktop came with 4 slots for memory. I order 32GB which means the first 2 slots are taken with 16GB sticks in each slot.  When I opened the case, I see the chips are Fury HyperX memory, but I can't get much more information unless I take a chip out, but I'd prefer not to.  So, does Dell provide these memory chips to buy or can someone tell me what memory speed these operate at so I can get a couple more? Thanks, Greg
Area-51 R5, would like to add 32 GB memory