A:Answer If you only have one HDMI port on the back of your television, and you have multiple items you wish to use that require HDMI ports, this switch box allows you to use one HDMI cord from the TV to the switch box, then you plug in up to 4 devices like DVD player, Chromecast, etc. to the switch box. Use the nifty little remote control that comes with the box to select which device you wish to use as you luxuriate in your recliner. The remote has an on/off button and buttons 1,2,3,4, to press that correspond to the device you wish to access. The remote comes with a battery installed. The box itself comes with a cord to plug into any 110 outlet.