the t.bone TWS 16 EarmiKeO 821 MHz Set@+*Bundle offer comprising*, the t.bone TWS 16 PT 821 MHz, 16 Channel UHF Wireless System, 9.5"" Diversity receiver, Bodypack (line / mic switchable), with 3-pin mini XLR connection (AKG compatible), 16 Switchable channels (821.725 MHz - 831.450 MHz), 4 Sets can be used