The ADDvox 7 Watt Voice Amplifier Kit is a speech amplifier with microphone headset designed for use by individuals with speech disabilities. It is designed to elevate the vocal volume of people with temporary or permanent voice impairments and to assist those who rely on an electronic speech aid, voice prosthesis or use esophageal speech. This system comes with the FeatherLite Pro Headset Microphone that features ear hooks designed to hook over the top of both ears with a back band to connect them. The amplifier/speaker unit is worn on the belt. A lapel microphone, standard microphone headset and travel case are included. The system was originally designed for theater professionals. POWER: The amplifier/speaker requires 8 rechargeable NiMH batteries (included). A charger is also included. OPTIONS: The charger is available in 110-volt or 220-volt models. WARRANTY: 1 year warranty.