SIIG DP eSATA 6Gb/s 2-Port PCIe Dual Profile PCI Express 2-Port eSATA 6Gb/s Host Adapter (SC-SA0M11-S1) ADDS 2 external SATA (eSATA) 6Gb/s channels to your PCIe system SIMULTANEOUS FUNCTION: Supports port multipliers: Up to 5 hard disks (max) on each eSATA port and up to 7 hard disks amongst the connected port multipliers. " VERSATILE INSTALLATION: Installs in standard height or low profile chassis with included brackets FULLY APPLICABLE: Works with the latest 6Gb/s SATA HDDs and is backwards compatible with 3Gb/s and 1.5Gb/s HDDs NOTE: The included Asmedia driver must be installed for port multiplier operation