The Synology RAM1866DDR3LSO-2G is a genuine OEM memory module designed specifically for the Plus + models. With a capacity of 2GB DDR3L-1866, it comes in a SO-DIMM form factor and has a total capacity of 2GB. This module is ideal for expanding the memory capacity of your Synology device, ensuring smooth and efficient performance for your computing needs.Synology offers expandable memory for their PLUS (+) versions of the DiskStations and this is a great way to add to your units' overall RAM.Used approximately 40 hours or so, upgraded to a different NAS which did not have expandable memory. So I was left with this extra stick.