This product is either discontinued or we cannot get that from suppliers.
QNAP TS-451D2-4G Desktop 4-Bay Diskless NAS Intel Dual-Core 4GB RAM, Intel Celeron J4025 dual-core 2.0 GHz, Intel HD Graphics 600, 4 GB SO-DIMM DDR4 (1 x 4 GB) , 4 x 3.5-inch SATA 6Gb/s, 3Gb/s, 2x Gigabit , 4x USB 3.2 Gen 1 port.
The 4-bay TS-451D2 provides high storage potential for home and small business users to store, share, and back up files. Business users can leverage its dual-core Intel processor to enable seamless multi-user on-premises/remote access to work files, while home users can enjoy.