Internal Mini Serial Attached SCSI HD x4 (SFF-8643) to Mini Serial Attached SCSI x4 (SFF-8087) cable Key Features Type: Adaptec 6Gb/s SAS HD Cables Compatibility: Series 7/7Q Adapters Dimension: 1 Meter The Adaptec ACK-I-HDmSAS-mSAS-1M is an internal Mini Serial Attached SCSI HD x4 (SFF-8643) to Mini Serial Attached SCSI x4 (SFF-8087) cable. It measures 1 meter and is used for connecting a SAS/SATA adapter to a SAS/SATA backplane.