The Loud Phone Ringer, model SR-1, is a telephone signal accessory designed for use by individuals who are hard of hearing. This ringer generates loud ringing from an analog telephone line or from a dry contact closure for non-telephone applications such as a push button doorbell, night bell, or "Push Button for Assistance" chime. Four selectable sound options include electronic warble; double gong; quadruple chime (four descending chime tones); or electronic bell. A volume control knob adjusts loudness to a maximum of 90 decibels at one meter. OPTIONS: 25AE Paging Horn to increase maximum sound level to 105 decibels. POWER: Uses the included alternating current (AC) adapter. DIMENSIONS (HxLxW): 5.5 1.6 x 4.5 inches. WARRANTY: One year.