The PEXUSB3S4V PCI Express USB (Universal Serial Bus) 3.0 Card (with SATA Power) adds 4 external USB (Universal Serial Bus) 3.0 ports to any PCI Express-enabled computer system. Super Speed USB (Universal Serial Bus) 3.0 provides up to 5 Gbps of data bandwidth while remaining backward compatible with existing USB (Universal Serial Bus) 2.0 devices at 480 Mbps. Using a stacked port layout that places the ports one on top of the other more ports are able to fit into a smaller space. This 4-port PCIe USB (Universal Serial Bus) 3.0 adapter enables all four USB (Universal Serial Bus) 3.0 ports to be external facing while still allowing the card to fit into a small form factor/low profile computer system. Plus with a built-in SATA power connector each USB (Universal Serial Bus) port can provide up to 900m A of power to devices that draw power from a host bus connection (500m A for USB (Universal Serial Bus) 2.0) by connecting to your computer power supply. The PEXUSB3S4V USB (Universal Serial Bus) 3.0 PCIe card is backed by a Star Tech.com 2-year warranty & free lifetime technical support. USB (Universal Serial Bus) 3.0 PCI-E card has 4 external USB (Universal Serial Bus) 3.0 ports using a space-saving stacked layout Dual profile (full-height & half-height) design fits into full or low profile/small form factor (SFF) systems Uses a SATA power connector for compatibility with newer systems that have limited or no LP4 power supply connections to ensure maximum power for USB (Universal Serial Bus) devices