468405-002 HP 3GB 24Ports PCI-E SAS Expander Controller Card

A SAS Expander Controller Card is a device that allows users to expand the number of SAS or SATA devices that can be connected to a single SAS or SATA port on a controller. SAS stands for Serial Attached SCSI, and it is a technology used in storage devices such as hard drives, solid-state drives, and tape drives. SATA stands for Serial Advanced Technology Attachment, and it is a technology used in hard drives and solid-state drives.

In short, a SAS expander controller card allows users to connect multiple SAS or SATA devices to a single SAS or SATA port on a controller, thus increasing the number of devices that can be used in a single system.