1.Internal Mini SAS SFF-8643 TO (4) 29pin SFF-8482 connectors with IDE power, connecting a SAS controller (SFF-8643) TO four SATA/SAS disks (SFF-8482).2.Mini SAS (SFF-8643) is host, 4 SAS 29 (SFF-8482) is target, internal Mini Serial Attached SCSI x4 (SFF-8643) TO (4) x1 (SFF-8482) Serial Attached SCSI (controller based) fan-out cables.3.Before you buy this cable, Please make sure the Mini SAS (SFF-8643) on your motherboard or RAID controller. If the Mini SAS (SFF-8643) on your backplane, this cable will not work with them.4.Mini SAS (SFF-8643) connect to the controller, 4 SAS connect to the HDD (hard disc driver).5.High Density (HD) Mini SAS connector SFF-8643 is the new connector, consumes less PCB space and allows higher port density for internal hosts and devices.