Synology DiskStation 4-bay DS423+ is a capable performer with all the tools you need to secure, share, back up, and sync your data and media. Built-in solutions available in Synology DiskStation Manager (DSM) let users create their own private cloud, organize and stream music, video, and photo collections across all devices, seamlessly collaborate with partners, set up an intuitive surveillance system, and more. 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 D4NESO-2666-4G ) Only use Peripherals listed on the compatibility list -https://www.synology.com/en-au/compatibility