They dont work. We have it plugged into the wall with an AC adapter (you can get one here on Amazon) and it not only charges our remotes but also keeps track of them. He has used these daily for several weeks and this was a good purchase. I have tried the 38 regular at the store and thought it to be a bit tight. The sound quality is good, will not compare to those hundreds of dollars headphones, it is really outstanding to the headphones at this price range. 5 hrs shifts on a very busy ward and suffer with really bad foot pain every day. Im probably lucky it lasted this long. The funnel works great for transferring spices. Keep in mind, that is emergency equipment. Ive dropped my Airpods Pro a dozen times from a few feet with no case, with no functional damage (irresponsible, I know), but I wouldnt trust these to survive the same treatment.