Headset Amplifier and Interface Module

- Provides headset interface for phone without a headset jack - Adjustable amplification of headset transmit and receive - Powered by 12V power supply (included) or 2 AA batteries (optional) - Headset On/Off button - Mute button - Headset volume control - In-use indicator LED - 3 RJ11 ports for headset, telephone handset, and telephone