The ATW-T902a System 9 Frequency-Agile VHF Wireless Handheld Transmitter and Mic from Audio-Technica is a frequency-agile, single-channel transmitter with a unidirectional dynamic capsule. This means that you can select any one of the four frequencies (169.505, 170.245, 171.045, and 171.905 MHz) and use up to four System 9 wireless systems at the same time, if each system is set to a different channel frequency.
The transmitter is designed to provide rock-solid performance and can be used when paired with a System 9 receiver (sold separately) to capture audio in vocal, speech, and presentation applications. It is equipped with an operating range of 200' and is powered by two AA batteries. In addition, the handheld transmitter will operate up to 8 hours.