The light I saw was yellow) The charger that came with the device is a Samsung charger so there should not be a problem. With covid and with med issues, going out to try on shoes was not an option. Cnet says they both have a "9" for sound quality. You cannot set two of these up with Bluetooth on the same device - that was my plan, but instead I’ve had to use the audio connection with a splitter2. I lay down a base layer of right out of the showere [you need to still be damp for the salt stick to apply properly] and then throw down this on top after Ive had a few minutes to air dry as Im getting dressed. That is important, since I am wearing it for 8 hours or more, comfort is of course very important. So I really love them, they are very comfortable for my tango lessons. The instructions clearly show an opening in the cover at the bottom but of course there is no such opening. It is incredibly comfortable, really really comfortable, but not the best choice to wear after swimming or beach shoes. The next morning (the day of my dads birthday) we woke up and I got out my amazon bag with these in it.