The Synology DX525 is a 5-bay expansion enclosure designed for seamless storage scalability with compatible Synology DiskStation models including DS1825+, DS1525+, DS925+, and DS725+. Supporting both 3.5" and 2.5" SATA hard drives and SSDs with hot-swappable drive bays for easy installation and replacement without powering down. Connects via USB-C expansion port with included cable for plug-and-play setup and immediate recognition through DiskStation Manager (DSM). Enables online volume expansion without interrupting storage or services on the host NAS, or serves as a dedicated local backup destination when configured as a separate volume for protection against system failure. Managed directly from DSM on the host NAS for unified drive management and monitoring. Hot-swap capability ensures uninterrupted operation during capacity expansion and maintenance. Add up to two DX525 units per compatible NAS for flexible storage growth. Ideal for businesses requiring on-the-fly capacity expansion for file servers, backup repositories, and growing data storage needs without service downtime. Includes USB-C expansion cable, AC power cord, and accessory pack. Backed by Synology's 3-year limited warranty with comprehensive hardware replacement and premium technical support, with optional Extended Warranty or Extended Warranty Plus available in select regions.