The channel pictured developed in the footbed of the left boot. The case is made very well and the sony case fits perfectly. Now on to the most important question, how do they sound?Bass - 9Mids - 9Highs - 9I was surprised how much the low end actually cut through, I recently wrote song that has an intro with an 808 kick and I was blown away that I could actually hear the 808! It was easy to connect and worked immediately. Also I have wide feet and so i got a wide width and they fit perfectly! Tal y como los esperaba padrisimos En las instrucciones me dicen que debo llevar el móvil y queen correos me darán una caja para su envío de forma que llegara de manera "segura" cuando llego y veo la caja. Poor quality, snapped in two after just a few months of use. Rebelnjjjnnnnnnnnjjjjjjjjjj jjjjj n j j n n n n jun n no n n n no n n n n n no. Not flat by any means, but foot tapping fun.