The Synology DS1522+ is a versatile 5-bay NAS solution that is easy to scale and expand as your needs change, with optional support for up to 15 drives, fast networking, and NVMe SSD caching. Powered by Synology DiskStation Manager (DSM), it offers a flexible all-in-one solution for data sharing, synchronization, backup, and surveillance..Extended Warranty - Extend warranty from 3 years to 5 Years with the additional purchase of EW201 ( Extended Warranty license must be registered at the same time as the NAS) , 8 GB DDR4 ECC SODIMM (expandable up to 32 GB)