The ACK-I-mSASx4-SAS4x1-FO-1M R is an internal mini Serial Attached SCSI x4 (SFF-8087) to (4) x1 (SFF-8482) Serial Attached SCSI (controller based) fan-out cable with removable power dongles. It measures 1 meter and is used for connecting a SATA/SAS controller (SFF-8087) to four SATA/SAS disks (SFF-8482).