Micron 2GB 1Rx8 PC3L-10600R Registered ECC DIMM, part number MT9KSF25672PZ-1G4D1AD. Memtest86+ passed, zero errors. Works perfectly.

Datasheet available here:

https://media-www.micron.com/-/media/client/global/documents/products/data-sheet/modules/parity_rdimm/ksf9c256_512x72pz.pdf