The vs421hd4k 4 port hdmi 4k switch lets you share a display or projector with four hdmi enabled audio video source devices the switch features four independent inputs that each support 4k resolution and 71 surround sound audio the 4 port switch also features mhl support on hdmi input port 1 enabling video output video from mhl enabled mobile devices such as samsung galaxy tablets and smartphones you39ll be amazed at how this video switch maintains ultra hd picture quality 4k is supported by