I love this product and believe in the skullcandy product lines so much. El sonido es bastante bueno, son algo incómodos al principio, tristemente tuve que devolverlos porque el audífono izquierdo tenía problemas con la batería, se agotaba primero que la del derecho y nunca se cargaba más del 90%. JBL should provide some fix immediately. Not likely to fit the first set. Rest quality. Easy slip on, soft, and warm, but they just dont fit right. The cover slid right on without any problems and fit well. For someone who is unfamiliar with the terms for foreign produced cell phones, international sounds like it would work internationally. That said, Im sure a 13 year old would love to dim the room lights and illuminate this headset. 4) Bass extension, the bass guitar riffs sound real on these to my untrained ears.