900 MHZ WIRELESS–TRANSMITS AUDIO SIGNAL THROUGH WALLS, FLOORS & CEILINGS AT DISTANCES OF UP TO 300 FT FROM TRANSMITTER; 2-WAY ACOUSTIC SUSPENSION DESIGN FOR HIGH-QUALITY SOUND; CONVENIENT PUSH-BUTTON AUTO-LOCK TUNING; BUILT-IN HANDLE FOR EASY PORTABILITY; LEFT/MONO/RIGHTS SWITCH OFFERS VERSATILITY & CONVENIENCE—SET UP WITH THE LEFT & RIGHT OPTION FOR STEREO MUSIC, OR SET TO MONO & PLACE SPEAKERS IN MULTIPLE ROOMS FOR WHOLE-HOUSE AUDIO; USE AS REAR CHANNELS IN A 5.1 SURROUND SOUND SYSTEM WHEN RUNNING SPEAKER WIRE IS NOT POSSIBLE OR PRACTICAL; DUAL POWER MODE–USE THE AC POWER ADAPTERS OR 8 C-CELL BATTERIES ; CHANNEL SELECT SWITCH PERMITS THE CHANGING OF TRANSMISSION FREQUENCIES TO OPERATE MORE THAN ONE 900 MHZ PRODUCT WITHIN THE SAME AREA; PAIR;