They Synology DS925+ is a capable 4-Bay NAS that can adapt to growing storage demands. With support for up to 9 drives with expansion unit, two M.2 NVme slots for caching and built in 2.5Gbe. Powered by Synology Disk Station Manager (DSM), if offers a flexible all in one solution for data sharing, synchronization, backup, and surveillance and is backed by a 3 year warranty. Must be used with SYNOLOGY HARD DRIVE ONLY.