TRANSMITS AUDIO SIGNAL THROUGH WALLS, FLOORS, WINDOWS & CEILINGS AT DISTANCES OF MORE THAN 250 FT FROM TRANSMITTER; IDEAL FOR OUTDOOR SETTING'S RUGGED DESIGN, YET STABLE ON UNEVEN SURFACES; EASY & RELIABLE TUNING—PHASE-LOCKED LOOP CIRCUITRY GUARANTEES A CLEAR AUDIO SIGNAL; RICH 360deg SOUND PROJECTS HIGH-QUALITY SOUND IN ALL DIRECTIONS; AUTOMATIC LEVEL CONTROL AVOIDS SUDDEN VOLUME BLASTS OR VALLEYS; LEFT, MONO & RIGHT SWITCH PROVIDES THE OPTION FOR STEREO OPERATION WITH THE USE OF ANOTHER RCAAW822 INDOOR/OUTDOOR WIRELESS SPEAKER; DUAL POWER MODE RUNS ON OPTIONAL BATTERIES OR THE SUPPLIED AC ADAPTER; CHANNEL SELECT SWITCH ALLOWS USER TO OPTIMIZE RECEPTION