The SolaTone(r) artificial larynx is a high quality, single tone speech aid that's very easy to use and easy on your budget. This instrument, based on a proven design, provides quick results by meeting your basic speech aid needs. You will love the independence offered by its light weight, simple design and 9 volt transistor battery operation. Never get stuck with a dead battery again! Insist on a 9v battery operated electrolarynx like the SolaTone(r) or TruTone(r) Electrolarynx devices.