The DS425+ delivers powerful functionality in a compact 4-bay, desktopfriendly design. Built-in 2.5GbE networking provides excellent network speeds out of the box. Powered by Synology DiskStation Manager (DSM), the DS425+ serves as a versatile all-in-one solution for data sharing, synchronization, backup, and surveillance.3-year hardware warranty, extendable to 5 years with EW201 ( additional purchase) Built-in M.2 2280 NVMe SSD slots permit cache acceleration without occupying storage drive bays Back up critical data and reduce your Recovery Time Objective (RTO) with Snapshot Replication Maximum IP camera: 25 (total of 750 FPS at 720p, H.264) (Including two free camera licenses; additional cameras require the purchasing of additional licenses) 2 GB DDR4 onboard (expandable up to 6 GB by adding 1 x D4NS01-4G ) Only use Peripherals listed on the compatibility list -https://www.synology.com/en-au/compatibility Enterprise Series M.2 2280 NVMe SSD: SNV3400 Series Optional Accessories DDR4 non-ECC SODIMM: D4NS01-4G Enterprise Series 3.5' SATA HDD: HAT5300 Series Plus Series 3.5' SATA HDD: HAT3300 Series Enterprise Series 2.5' SATA SSD: SAT5200 Series