simolio 2.4g wireless tv headsets with 100ft transmit range, no pairing, no delay, tv voice highlighting headphones for seniors, wireless tv headphones with extra soft earbuds (sm-823 pro) simolio <b>important!</b><br>1.before purchasing, check audio output of your tv/audio source first, make sure it has red/white jacks labeled as "audio out". if only with optical audio out jack, then you need headset model with optical in, such as sm-823d pro, sm-824d1.<br>2.if you experience no sound, sound cuts in and out, only hear at one side, most are caused by operational issue. pls refer to the user instructions or reach to support(at)simolio.com. we are confident to get one good solution for you.<br>3.the under-chin headset weighs 2.04 oz, to some too small or sensitive ear canals, we suggest to buy simolio wireless tv speaker sm-621d or over-ear tv headphone sm-825d pro as alternative.<br>4.place the base as far away as possible (at least 4 feet)from wifi tv/tv stick.<br>5.very helpful for moderate hearing impaired people.<br><br>features:<br>(1)advanced 2.4ghz digital fhss tech, much better than ir, no interruption when people passing by, operation is up to 100 feet in open range; superior to bluetooth,no any lip-sync delay, brings superb sound reproduction.<br><br>(2)adjust the sudden changed high volume to protect hearing via auto signal control.<br><br>(3)customize a comfortable volume level via balance & tone adjustment.<br><br>(4)with voice highlighting & noise cancelling tech, it dynamically reduces tv background sound and highlights the tv dialog, thus ensure a better understanding for the tv story.<br><br>(5)mono/stereo option, we suggest to select mono to increase the recognition of dialog for people hard of hearing.<br><br>(6)it overcomes the weakness of regular hearing aid which amplify the target audio sources and environmental noises at the same time.<br><br>(7)the built-in mic make you amplify people’s voice nearby.<br><br>(8)auto power off when no signal is received for 10 min.<br><br>(9)replaceable battery & convenient charging dock, one full charge supports 5~7 hours working.