... is for optional power. Active USB extension cable with 2 USB hub DescriptionThis is an USB active extension cable ... be used to increase the length up to 5m. With this cable, you could extend two devices, like keyboard ... at the same time. Specification1. Compatible with USB 2.0 speed, up to 480Mbps;2. Self-powered for USB cameras, printers ... .6 or Later. Active USB Extension Cable with 2 USB HUB CU1064