This keypad plugs into the UHBX-SW3-WP using a CAT5 cable and can be located up to 200 ft away at a convenient location. The SW3-UI-VOL duplicates all the controls and indicators that are on the wall plate. It is perfect for monitoring and controlling the system from a convenient spot instead of using the buttons on the UHBX-SW3-WP wall plate. The SW3-UI-VOL adds 3 additional buttons that can be tied to volume commands of your display. These additional buttons do not change the volume embedded in the HDMI output, but they are meant to send Volume Up/Down, Mute, and Unmute commands to the projector or display.