This helmet is fabulous, it has the advantages of Hifi headphones without having the inconvenience !!! => It ranks very easily, is comfortable and it does not effect the sauna in the ears that I felt with other headphones! But the biggest highlight is the sound rendering !!!! As much in severe than in the treble, in a bedroom or in the subway, with or without batteries, quality is sublime !! I am very happy with this purchase. I recommend it strongly!