The CrystalTone is a large button amplifier telephone designed for use by individuals who are hard of hearing. This phone increases incoming voice volume volume up to 35 decibels(dB), enhances sound quality and enables the user to customize volume, tone, and hearing frequency. CrystalTone control eliminates background noise and enhances sound. The push-button volume control turns amplification on and off, enabling the phone to be used by those not requiring amplification; when the amplification is turned back on, it returns to the user's settings. Other features include outgoing voice amplification; a ringer adjustable to 100 dB; adjustable ringer pitch; visual ring light; 13 memory buttons, including three emergency keys; an audio jack; a hearing-aid compatible handset; redial button; flash button; hold button; and an extra-large high-contrast dial pad. WARRANTY: One year.