Single-channel UHF wireless microphone system; Unique snap-out panel locking tabs for optional single receiver rack mounting or side-by-side rack mounting; Tone Squelch(TM) for locking out interference; 120dB range; UHF-4 receiver with DigiTRU Diversity(TM) for maximum range & dropout protection; Full LED indicator lights; UH-4 transmitter ; Choice of instrument, headworn or lavalier microphone operating modes; Off/standby/on switch allows convenient audio muting ; 3.5mm input for microphone or instrument cable; Uses single 9V alkaline or NiMH battery;UH-4 handheld microphone transmitter:; Nady(R) DM-10D unidirectional neodymium dynamic cartridge for optimum sound, maximum feedback rejection & minimal handling noise; Off/standby/on switch allows convenient audio muting ; Full LED indicator lights; Uses single 9V alkaline or NiMH battery;