simolio 2.4g digital wireless tv headsets with spare battery, tv listening wireless headphone with voice highlighting,tone & balance control, support optical/rca/aux, 100 ft range, no delay sm-824d1 simolio <b>important!</b><br>1.before purchasing, please make sure the audio out format of your tv and tv related av device are compatible with pcm or can be set to pcm format.<br><br>2.if you experience no sound, sound cuts in and out, only hear at one side, most are caused by operational issue. please refer to the user manual and quick guide or refer to our simolio support team. we are confident to get one good solution for you.<br><br>3.the under-chin designed headset weighs 2.04 oz, some people may not get used to this design, to some too small or sensitive ear canals, we suggest to buy simolio wireless tv speaker sm-621d as alternative.<br><br>4.place the transmitter 4 feet away from wifi tv box/tv sticks.<br><br>5.digital wireless headphone for smart tv, very helpful for moderate hearing impaired people.<br><br><b>features</b><br>(1) adopts advanced 2.4ghz auto fhss tech, much better than the ir tech, there is no interruption when people passing by, operation is up to 100 feet in open range; superior to bluetooth, there is no any lip-sync delay, brings superb sound reproduction to you.<br><br>(2) spare battery & convenient charging solution support sustained tv enjoyment.<br><br>(3) adjust the sudden changed high volume to protect your hearing via auto signal control (asc).<br><br>(4) customize a comfortable volume level via balance & tone adjustment.<br><br>(5) benefit from voice highlighting & noise cancelling tech, it dynamically reduces tv background sound and make the tv dialog stand out which ensure a better understanding of the tv story.<br><br>(6) mono/stereo optional, we suggest to select mono to increase the recognition of dialog for the people hard of hearing.<br><br>(7) it overcomes the weakness of regular hearing aids which amplify the target audio sources and environmental noises at the same time.<br><br>(8) the built-in mic make you amplify people’s voice nearby.<br><br>(9) headset with auto power off when no signal is received.