No wear and tear on the USB port. mANY OF THE NEWER BIKES DO NOT HAVE THE NARROW TUBES THROUGHOUT THE FRAME ANYMORE AND SO IF YOU ARE CARRYING OLDER BIKE IT WOULD WORK WELL BUT ID YOU HAVE NEWER AERODYNAMIC STYLES OR HIGHER END BIKES THEY WILL BREAK. Let me be frank: the headphones as listening devices are great; super light, easy on the ears, stylish. ) and not a refund. I work a minimum of 8 hours a day on my feet in a fast paced restaurant. It?s not a powerful latch but I have never had it pop open on its own. Hoped these would alleviate my plantar fasciitis, but they wont stay on my feet, just slide right off as soon as I try to walk. Very pleased with item. If you flip the little lid you can see a dot that turns orange if they need charge or green when fully charged. It was very difficult to zip from the ground but if you don?t over load it you can do it easy.