900 MHZ WIRELESS—TRANSMITS AUDIO SIGNAL THROUGH WALLS, FLOORS & CEILINGS AT DISTANCES OF UP TO 300 FT FROM TRANSMITTER; OMNI-DIRECTIONAL DESIGN PROJECTS HIGH-QUALITY SOUND IN ALL DIRECTIONS; HIGH-EFFICIENCY DIGITAL AMPLIFIER HELPS EXTEND BATTERY LIFE; CONVENIENT PUSH-BUTTON AUTO-LOCK TUNING; WATER-RESISTANT DESIGN FOR USE OUTDOORS & INDOORS IN HUMID AREAS, SUCH AS KITCHENS & BATHS; BUILT-IN HANDLE FOR EASY PORTABILITY; DUAL POWER MODE – AC ADAPTER OR BATTERIES; LEFT/MONO/RIGHTS SWITCH PROVIDES THE OPTION FOR STEREO OPERATION WITH THE USE OF ANOTHER RCAAW811; CHANNEL SELECT SWITCH PERMITS THE CHANGING OF TRANSMISSION FREQUENCIES TO OPERATE MORE THAN ONE 900 MHZ PRODUCT WITHIN THE SAME AREA; EACH