Expansion Unit DX525
Seamless capacity expansion for Synology DiskStation
Overview:
Seamless capacity expansion for Synology DiskStation
Easily add five additional drive bays to your Synology DiskStation. The DX525 supports both 2.5" and 3.5" SATA drives and features plug-and-play setup and hot-swap capability for uninterrupted operation during capacity expansion.
- Capacity Expansion
Add 5 additional 3.5"/2.5" SATA HDD/SSD to your DiskStation - Fast and Intuitive Setup
Configure new storage in minutes with Synology DSM's unified tools - Uninterrupted Storage Expansion
Add new volumes or expand current volumes without service interruptions - Extendable Product Support
Backed by Synology's 3-year limited hardware warranty, extendable to 5 years in select markets
Features:
Dedicated local backup solution
The Synology DX525 provides a dedicated local backup solution for your Synology DiskStation. When configured as a separate volume, it safeguards data on its local disks in case of system failure.


Online volume expansion
Managed through the host NAS's DiskStation Manager (DSM), the DX525's additional bays are immediately available upon connection. On-the-fly volume expansion ensures uninterrupted service and storage expansion on the host.
Rapid Deployment
Handle both scheduled storage upgrades and sudden demands with ease. With plug-and-play compatibility and support for hot-swapping drives, the DX525 is ready to use as soon as it’s connected to the host device, allowing for drive installation without powering down the system. Online volume expansion means that volumes can added or expanded without service interruptions.
Technical Specifications:
Hardware Specifications: | |
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Applied Models |
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Storage | |
Drive Bay(s) | 5 |
Compatible Drive Type |
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Hot Swappable Drive | |
RAID Management through Synology DSM | |
Appearance | |
Size (Height X Width X Depth) | 166 mm x 230 mm x 223 mm |
Weight | 2.46 kg |
Power | |
Power Recovery | Synchronized with the Synology DiskStation |
Power Supply Unit / Adapter | 90W |
AC Input Power Voltage | 100V to 240V AC |
Power Frequency | 50/60 Hz, Single Phase |
Power Consumption* |
35.37 W (Access) 7.0 W (HDD Hibernation) |
British Thermal Unit |
120.69 BTU/hr (Access) 24.02 BTU/hr (HDD Hibernation) |
Note | Power consumption is measured when fully loaded with Toshiba 600GB AL14SEB060N hard drive(s). |
Temperature | |
Operating Temperature | 5°C to 40°C (40°F to 104°F) |
Storage Temperature | -10°C to 70°C (-15°F to 155°F) |
Relative Humidity | 5% to 95% RH |
Others | |
System Fan | 92 mm x 92 mm x 2 pcs |
Noise Level | 20.4 dB(A) |
Note | Noise Level Testing Environment: Fully loaded with Seagate 1TB ST31000520AS hard drive(s) in idle; Two G.R.A.S. Type 40AE microphones, each set up at 1 meter away from the Synology NAS front and rear; Background noise: 16.49-17.51 dB(A); Temperature: 24.25-25.75˚C; Humidity: 58.2-61.8% | Certification |
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Warranty | 3-year hardware warranty, extendable to 5 years with EW201 or Extended Warranty Plus |
Applicable Extended Warranty | EW201 - 2 Year Extension |
Environment & Packaging | |
Environment | RoHS Compliant |
Packaging Content |
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Optional Accessories |
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*Model specifications are subject to change without notice. Please refer to www.synology.com for the latest information.
Documentation:
Download the Synology Expansion Unit DX525 Datasheet (PDF).

Synology has you covered
The DX525 is backed by Synology's three-year limited warranty, including technical support and hardware replacement services. Extend your coverage to five years and gain access to premium services that accelerate recovery in the event of a disaster with Extended Warranty Plus.
- All Prices are Inclusive of GST
- Pricing and product availability subject to change without notice.