This HDMI switcher has four inputs and one output, and it differs from other HDMI switchers on the market because it also has TOSlink Optical inputs as well as Digital PCM (RCA) inputs, allowing you to Output HDMI, TOSlink and PCM (RCA). This is absolutely perfect as an all in one solution for your home cinema or digital signage requirements as it is 1080p Full HD compatible and it can also be controlled using RS-232 PC connection.