This bi-directional Toslink (digital optical audio) switch serves as either a 3x1 switch or a 1x3 switch.
As a 3x1 device, the switch allows you to select one of up to three input devices to direct to the single output. As a 1x3 device, the switch works in the opposite direction, allowing you to direct a single input to one of up to three output devices.
This switch provides full optical clarity and will not degrade the optical signal in any way.