The sthdbtrx works with the st424hdbt hdmi matrix switch to extend an hdmi audiovideo source up to 230ft 70m over cat5e6 cabling one sthdbtrx receiver unit is required for each individual remote display together with the st424hdbt the cat5 hdmi receiver works to create a digital signage solution that eliminates the expense and hassle of running multiple devices with an hdmi matrix switch and extender in one clutter free system because the signal is extended using standard cat5e6 etherne