Used but in good condition.

4 Bay NAS with 2x 2.5Gbe Lan, includes 4 drive sleds with screws.

Specs.

TS-451DeU-2G

CPU Intel® Celeron® J4025 2-core/2-thread processor, burst up to 2.9 GHz
CPU Architecture 64-bit x86
Graphic Processors Intel® HD Graphics 600
Floating Point Unit
Encryption Engine (AES-NI)
Hardware-accelerated Transcoding
System Memory 2 GB SODIMM DDR4 (1 x 2 GB)
Maximum Memory 8 GB (2 x 4GB)
Memory Slot 2 x SODIMM DDR4
For dual-DIMM configuration, you must use a pair of identical DDR4 modules.
Flash Memory 4GB (Dual boot OS protection)
Drive Bay 4 x 3.5-inch SATA 6Gb/s, 3Gb/s
The system is shipped without HDD.
For the HDD compatibility list, please visit https://www.qnap.com/compatibility/
Drive Compatibility 3.5-inch SATA hard disk drives
2.5-inch SATA hard disk drives
2.5-inch SATA solid state drives
Hot-swappable
M.2 Slot 2 x M.2 2280 SATA 6Gb/s slots
SSD Cache Acceleration Support
2.5 Gigabit Ethernet Port (2.5G/1G/100M) 2 (2.5G/1G/100M/10M)
Wake on LAN (WOL)
Jumbo Frame
USB 2.0 port 2
USB 3.2 Gen 1 port 2
Form Factor 1U Short Depth Rackmount
LED Indicators Power/Status, LAN, USB, HDD1-2, M.2 SSD 1-2
Buttons Power, Reset
Dimensions (HxWxD) 44 × 430 × 295 mm
Weight (Net) 4.15 kg
Weight (Gross) 5.79 kg
Operating Temperature 0 - 40 °C (32°F - 104°F)
Storage Temperature -20 - 70°C (-4°F - 158°F)
Relative Humidity 5-95% RH non-condensing, wet bulb: 27˚C (80.6˚F)
Power Supply Unit 100W PSU, 100-240V
Power Consumption: HDD Sleep Mode 13.18 W
Power Consumption: Operating Mode, Typical 28.02 W
Tested with drives fully populated.
Fan 3 x 40mm
System Warning Buzzer