It is a portable assistive listening and personal monitoring belt pack transmitter using 17 VHF channels with frequencies in the 72 to 76MHz band. It is lightweight, battery operated and equipped with small electret lapel microphone. The PST-170 has side panel auxiliary input designed to connect audio devices such as tape players and microphone input located on the top panel. The selected channel is displayed on backlit LCD and may be locked to prevent accidental changes. This unit is recommended for churches, museum tours, conferencing and educational applications.