The VS?401USB is a high?quality 4×1 USB switcher. It accepts up to four USB devices and switches the selected device to the host. – High–Speed USB — Ver 2.0. – Flexible Control Options — Front panel buttons, RS–232 & IR remote (included). – Firmware Upgrade — Via RS–232 using K–UPLOAD application software. – Compact Kramer TOOLS™ — 3 units can be rack mounted side–by–side in a 1U rack space with the optional RK–3T rack adapter.