84D-Link DNS-722-4/DNS-726-4 User ManualAppendix C - Technical Specifications+ Quick Installation Guide+ Power Cable Holder+ Keys+ CD-ROM with:- Software- Product DocumentationRemark 1: An external SATA drive is required to store or share files. (Not included.)Remark 2: RAID1 mirroring requires the use of two internal SATA drives. To avoiddata incompatibility in RAID 1 operation, use identical SATA drives from the samemanufacturer. Formatted drive capacity for RAID 1 operation is dependant on the drivecapacity of the lowest-sized drive. Some older generation SATA drives may not becompatible. For a list of SATA drives that have been tested to work with the DNS-722-4/DNS-726-4, visit the D-Link support web site.