2 Ports USB 3.0 to Motherboard 20Pin Extension Cable 50cm with Panel Mount Holes Stackable Female connector with Screw Panel Mount Holes. Offers a throughput of up to 4.8Gbps when used with a USB 3.0 host and device,an astounding 10x the capability of USB 2.0 (480Mbps). Backwards compatible with USB 2.0 1.1 1.0. Length about: 50cm.