These are 16GB DDR4-2666 RDIMMs that were pulled from working servers in an enterprise environment. They are Micron modules under their Crucial branding. Crucial model number: CT16G4RFD4266.36FB2 Micron model number: MTA36ASF2G72PZ-2G6B2QG

Note: These are registered DIMMs and will not work in systems that do not accept registered memory, please ensure your system supports registered memory before buying.