The Step Hear SH-200 Base, model 541016, is an audible and voice output electronic mobility aid designed for use by individuals who are blind or have low vision. Designed to help the visually impaired person navigate in unfamiliar areas, this system is equipped with expandable base units and a wrist-worn activator that begins to vibrate when the user is in range of a base. Pressing a button on the activator triggers a pre-recorded message from the battery operated base unit. An unlimited number or bases (for multiple locations) and activators (for multiple users) can be used simultaneously. Features include an indoor/outdoor waterproof base unit, support for MP3 audio input for recorded messages, support for three different recordings, and automatic adjustment of playback volume according to ambient noise levels. Large- scale applications could provide accessibility in a hotel or convention; small scale applications could provide assistance to orientation and mobility (O & M) instructors. POWER: The base using alternating current (AC). Solar powered bases are available upon request.