Sodium Benzoate added now with new formula. Im a 50yr, plus size woman with tired feet and I can wear these every day. She really like these and they were a great price plus its wireless. I was looking for an electric shaver, do not want to deal with disposables anymore and found this. The only thing I want to note, but its a personal preference/issue - the right bud seems to fit a little funny in my right ear. You can also see the wear on the older pair in the individual shots of the same sandals. Well, that was a mistake. 4 / 4Low . Li ho presi in due colori. A really good little charger.