ez-Pro VS4 is a 4 channels video switcher. It has 3 x HDMI, 1 x SDI , and 1 x HDMI/SDI interchangeable ports for inputs. You can monitor videos through 1 x HDMI Multiview, and display Program output through either 1 x HDMI and/or 1 x SDI. ez-Pro VS4 also receives TS type 6.35mm (1/4") Balanced External Audio ports, and sends out audio through 3.5mm Stereo port.