The cover of the insole is leather. Bass notes are easy to hear without them blending into an overall bass boom. It is amazingly smooth. Ive included a SOCC (straight out of camera) that is totally unedited. I am concerned about losing or damaging the original USB charging/connection cable since there seems to be no way to replace it. It is black with a poodle and a vulgar phrase on both sides. I ordered this in the large wide size (size 9-10) in both the navy blue and leopard print. It broke within a week but I just replaced it with one I had lying about. I finally came to the realization that my not so old sneakers were the culprit. With the legs extended, my bike does not tip over, no matter where it is positioned on the horizontal boom.