The PT4500 is an analog reference wireless body-pack transmitter with supreme wireless audio quality for instrumental and vocal use. The pilot tone prevents unexpected system startup noise, continuously sending transmitter data, including mute switch position and remaining battery life, to the receiver. An optional RMS4000 external mute switch allows the user to mute the transmitter remotely. WMS4500 transmitters offer an unmatched battery life of 15 hours with two standard AA-size alkaline batteries. With the integrated charging contacts, the optional BP4000 battery-pack can be charged inside the transmitter.