This product is either discontinued or we cannot get that from suppliers.
QNAP TS-451+-8G 4 Bay Diskless NAS, Quad-Core Intel® Celeron® 2.0GHz (burst up to 2.42GHz), 8GB DDR3L RAM (2 x 4GB), 4x 2.5" or 3.5" SATA 6Gb/s, 3Gb/s HDD or SSD; hot swappable trays, 2x Gigabit RJ-45 Ethernet ports, 2x USB 3.0 Ports (Front: 1, Rear: 1), 2x USB 2.0 Ports (Rear), 1x HDMI Port.
The TS-451+ is powered by a 64-bit Intel® Celeron® quad-core 2.0GHz processor and has 2GB/8GB energy-efficient DDR3L RAM (upgradable to 8GB) and dual Gigabit LAN ports, delivering up to 225 MB/s read & write speeds with port trunking mode.