Simply Plug it in The AS6004U utilizes a USB 3.0 connection cable. Simply plug it into any ASUSTOR NAS to complete hardware expansion! Depending on the model, ASUSTOR NAS devices can simultaneously connect up to 3 AS6004U units, satisfying the high capacity storage demands of enterprise users. Safety Bracket for Secure Connections The security bracket and mounting hole design allow the AS6004U and USB cable to be connected securely without having to worry about disconnections. Secure Disk Tray Lock Design In order to help users avoid accidentally pushing disk tray buttons and releasing hard disks during operation, ASUSTOR has added a new lock mechanism to its hard disk trays. The lock's flat-head design ensures that users will not need any special keys or tools to unlock it, only a simple flat-head screw driver. The new disks trays can be used with all ASUSTOR NAS devices, providing an additional layer of security for applications requiring the frequent swapping of hard disks (e.g., MyArchive). Smart Power Saving The AS6004U has a power sync mechanism that syncs it with the NAS's operation status. When the NAS enters sleep mode or powers off, the AS6004U will enter into standby mode. When the NAS resumes normal operation, the AS6004U will resume mounting. This function works to help users save significant power. Smart Fan Temperature Control Under heavy loading and operations, the system internal temperature will increase. The AS6004U utilizes fans with a wide speed range that support a temperature control function combined with a smart speed mechanism. When the system load and temperature increases, the fans will automatically increase their speed to cool the device allowing the system to maintain a suitable operation temperature, providing stable performance and service. Secure Storage The AS6004U features 4 hot swappable disk bays and is compatible with largest hard disks on the market. It supports RAID and AES 256-bit encryption, providing optimal data protection mechanisms. Flexible Storage Expansion and Backup In addition to providing an economical high capacity storage space, the AS6004U also supports ASUSTOR's MyArchive cold backup technology. This allows users to create removable storage archives at any time, and backup important data to them. First-Class Product Warranty All ASUSTOR NAS products come with a 3-year warranty. ASUSTOR continues to make customer service a priority in providing the highest standard of after-sales service and technical support.