The PEXUSB3S4V PCI Express USB 3.0 Card (with SATA Power) adds 4 external USB 3.0 ports to any PCI Express-enabled computer system. SuperSpeed USB 3.0 provides up to 5 Gbps of data bandwidth while remaining backward compatible with existing USB 2.0 devices at 480Mbps.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 3.0 adapter enables all four USB 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 port can provide up to 900mA of power to devices that draw power from a host bus connection (500mA for USB 2.0) by connecting to your computer power supply.The PEXUSB3S4V USB 3.0 PCIe card is backed by a StarTech.com 2-year warranty and free lifetime technical support. USB 3.0 PCI-E card has 4 external USB 3.0 ports using a space-saving stacked layoutDual profile (full-height and half-height) design fits into full or low profile/small form factor (SFF) systemsUses a SATA power connector for compatibility with newer systems that have limited or no LP4 power supply connections to ensure maximum power for USB devices