SIIG's 4-Port USB 3.0 PCIe easily adds four external Super Speed USB 3.0 ports to your PCIe-enabled desktop computer. This USB 3.0 adapter features per-port over-current protection to protect your connected device(s) and the adapter itself from unforeseen power surges and offers full backward compatibility with USB 2.0 and 1.1 devices while allowing for simultaneous connection of multiple USB 3.0/2.0/1.1 devices. The 4-port USB 3.0 PCIe delivers power and performance enabling you to meet all your daily computing needs.