the t.bone IEM 150 R - 640 MHz
the t.bone IEM 150 R - 640 MHz, UHF Stereo In-Ear Bodypack Receiver, For the IEM 150 system, Frequency range: 640 - 665 MHz, Stereo mix / mono operation, 3.5 mm Headphone jack, Volume control, Balance control, LED display, Belt clip, 2x AA battery or rechargeable battery, Includes earphones, silicone ear tips