Is the 4TB SSD storage included in the package, or do I need to purchase it separately?

The 4TB SSD storage is included in the package, but installation is required.

Questions & Answers: Synology DiskStation DS920+ NAS Server for Business with Celeron J4125 Quad-Core CPU, 8GB DDR4 Memory, 4TB SSD Storage, Synology DSM Operating System

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Synology DiskStation DS920+ NAS Server for Business with Celeron J4125 Quad-Core CPU, 8GB DDR4 Memory, 4TB SSD Storage, Synology DSM Operating System

Synology DiskStation DS920+, made for a variety of server roles such as backup, file storage, email servers, and domain controllers!
Celeron J4125 Quad-Core 2.0GHz 4MB CPU; 8GB (2 x 4GB) DDR4 PC4-21300 2666MHz SO-DIMMs; File Storage: 4TB (4 x 1TB) SATA III Solid State Drives for Ultra Fast Storage; 2 x RJ-45 1GbE LAN Port (with Link Aggregation / Failover support); 2 x USB 3.2 Port; 1 x eSATA Port
Features: Cache Acceleration (2 available M.2 SSD Slots), Virtual Machine Manager, Security Advisor, AES 256-bit Encryption, 2 Factor Authentication, Surveillance Station Suite, 4K Multimedia Server role, Desktop Backup, Hyper Backup, Snapshot Replication, Synology Drive, and many more
Synology NAS chassis comes in a sealed box.
Hard drives and memory upgrades included separately NOT installed, installation required.