The IR-310M is a lightweight, hands-free infrared wireless microphone. It is designed for use in the school classrooms and eliminates problems with interface or eavesdropping, allowing simultaneous use in adjacent classrooms. It is capable of operating on one of two selectable IR frequencies and two transmitters can work simultaneously. It is also capable of operation with one piece of rechargeable AA Ni-MH battery IR-200BT-2 for continuous operation up to 8 hours.