Walkers Game Ear HD Elite Digital Hearing Aid Communicator Package with Three program settings (Communication Enhancement and combined Communication and Enhancement) Adjustable Frequency Tuning - AFT 50dB of hearing enhancement 4 digital sound processing channels 20-bit audio processor for crisp clear sound 8-band graphic equalizer Nano-Tech Water repellant coating Automatic feedback control Toggle volume control Sound activated compression (SAC) Low battery tone indicator Noise reducing rating NRR 29db Power source: #13 battery. Includes Unit PTT microphone loop sound tube/earplug batteries and carrying case.