The CO2 is a compact and rugged digital audio tool that converts S/PDIF signals from optical to coax and from coax to optical. Its 2-in, 2-out design allows the CO2 to operate as a full-duplex, bi-directional converter, or as a half-duplex converter with thru portallowing it to work as both a converter and a repeater. The CO2 is also affordable enough that its easy to add several if needed.