The Adaptec ACK-I-rA-HDmSAS-4rASATA-SB-.8M is an internal "right angle" Mini Serial Attached SCSI HD x4 (SFF-8643) to "right angle" (4) x1 Serial ATA fan-out cable with sideband signals (SFF-8448). It measures 0.8 meters and is used for connecting a SAS/SATA adapter to SATA disks, or a SAS/SATA backplane.