See update belowI purchased these on Dec 17th and overall we're very pleased, they're for my wife. Her hearing is bad in one ear and very bad in the other, hearing aids give some comfort but they're not perfect. With these headphones she can set the volume to a level not available on her other hearing aids (headsets, buds etc.).Closed captioning on television is nice to have but it's not always as smooth as we'd like and the placement on the screen can be annoying. She has tried a variety of headsets and ear buds over the years but none of them were 'very' good. This headphone set we heard about from a friend represents the proverbial 'godsend'.The volume level on these headphones is pretty amazing, I didn't realize how loud they could be set until I put them on one day to test them and almost "blew one ear off" :-) had to quickly rip them off my head. So, be warned, these are not the typical headphone and caution should be exercised where they're kept if small children are around. It would also be nice if each ear could be adjusted separately, if you have one good ear and one bad ear you're going to be limited how high you make the volume for the bad ear.The first thing she noticed other than being able to hear clearly again was she could walk around the house (2400 sq ft) and still listen without interruption. :-)We did end up having one problem though. We traveled to visit friends out of state and I was not able to get them working on the Marriott hotel's LG television (55LX340H) no matter what I did even with the Optical connection being detected. Of course, these specialized, commercial, hospitality-grade televisions don't allow guests to get into Settings to make any adjustments so I was 'fighting with a short stick' as they say.Strangely(?), the headphones would not turn on as if the batteries were not charged. The green light on the Transmitter Charging Dock was on and never went off. Pressing the Power button did nothing BUT viewing it in low-light conditions I could barely see a very dim red light if I held the power button down so thought the batteries were at end-of-life. This was very disappointing for my wife and she spent the week with closed-captioning.I was hoping when we got home they would miraculously start working again...unh unh, not so. Anyway I left them setup and over a couple of days tried turning them on occasionally. I did try other rechargeable batteries that we use in our Panasonic home phone system but they were not recognized, guess they really mean it when they say use ONLY their batteries. So, I went to their site and tried ordering their batteries but the Website did not play well, their "three_d_secure Gateway Rejected..." the transaction as it detected inaccurate information. I tried half a dozen times and gave up, also tried with different Browsers and computers to no avail.And then, totally unexpected now, they started working again, couldn't believe it! My wife is very happy with the 'resurrection' and they continue to work as expected. During this diagnostic phase I also learned there's an Audio EIA connector on the bottom of the left earpiece I hadn't noticed and with the accompanying Audio EIA cable we're able to connect to her cell phone and to the Panasonic house phones with an adapter. Wow, is she happy! https://smile.amazon.com/Josi-Minea-Converter-Headphone-Earphone/dp/B011S90G46/So, I finally went to Avantree's Support page and submitted a ticket. I heard back quickly from Sara and she was very helpful. I was able to submit an RMA Order for no charge and have received their batteries. I'll wait until I need them before checking them out.In the meantime while all this was going on I had gone to Amazon and ordered the Avantree batteries but they won't be delivered until January 30-31.Again, my wife is very pleased with this purchase and I'm happy the Support is so responsive.UPDATE: 8/5/2022Well, it happened again, the earphones would not power on no matter what I did. I 'dug out' the batteries they sent me for the last incident (above), put them in my charger and then replaced the ones in the set that were 'still' fully charging. You guessed it, didn't fix it, played around with it for another 3 or 4 days and just couldn't get them to power on.I finally went back to the Avantree support page and filled out another ticket describing the issue and referencing the previous ticket. This time Jeany from Support made the decision to send us a replacement set; it arrived about a week later and BINGO, it worked 'as advertised' ?.I'm guessing the original set we bought had some kind of defect that was elusive, the fact the issue occurred and then miraculously started working on its own . . . and then 6 months later did the same thing. The current set is a newer model and haven't seen any complaints about it so I'm confident it was one of those 'duh moments'.I still highly recommend this set, find myself 'borrowing' it when my wife's not around ? to plug into my tablet with the EIA cable so I can watch my videos with much better audio fidelity. Note when you use the EIA cable to connect to your phone or tablet you do NOT need to turn the power on, just think of them as 'big Buds'.