The URX60 professional digital UHF wireless microphone system is an excellent choice for a cost-efficient, high-performance multichannel system. With over 90 Selectable frequencies, Up to 24 channels can be used simultaneously. The Microphone uses Phase Lock Loop (PLL) technology for frequency control. PLL is a control system that generates an output signal whose phase is related to the phase of an input signal and provides great freedom from RF interference, and outstanding signal reliability.