The Azden IRN-10 Dual-Channel Selectable Neck-Worn Microphone/Transmitter is a lightweight, chest worn, microphone/transmitter. It comes with an adjustable lanyard. It is both a microphone and infrared transmitter which wirelessly "links" the teacher to the IRR-30P receiver. It has a specially designed internal microphone array which provides great sound pick-up. With two switchable channels, a teacher can go from classroom to classroom with the same microphone. With just two "AA" batteries (alkaline or rechargeable) the microphone can be used the entire school day without re-charging or changing batteries.