The popular Telex/RTS earpiece set is precisely designed for inconspicuous listening while on camera. Used by nearly all major television networks and stations, we have surpassed industry expectations. The extremely efficient miniature driver element requires only nominal operating power and enables the announcer to hear program cues while working with a live microphone. The units are also suitable for many other applications such as live theater script prompting. The CES-2 is a complete earpiece set. It includes the RTV-04, CMT-98, ET-4, cord, & 1/8" (3.5mm) plug.