They promptly replied and they are going to credit me for these since they are still under the warranty period. Theyre $20. Promptly returned. The bones and tissue of your skull conduct sound as well as a brick wall, so if they call this "bone conducting technology", any speaker could be said to have "wall conducting technology" if you listen to it through a wall. Seem to be designed for a Hobbit shaped foot! Regardless, a really nice touch by the Xiaomi team. These are really big and bulky and the adhesive that domes with it doesn?t stick, and because of the rounded backs of the trackers, any adhesive really doesn?t work. It was easy to assemble and learn how to control, even for our 7 and 9 year old. Couldnt be happier. El noise canceling es impresionante aunque también se puede desactivar, aunque no aconsejo su uso en la calle con el noise canceling activo porque realmente no se escucha nada, pero si necesitas privacidad en el avión o tu apartamento estos son los ideales!