Purchased this to replace an AfterShokz Titanium that lasted for just past the two-year warranty before the unit refused to charge any longer. Ill attach a pic to show the back. The noise cancellation works well, and no cords to get tangled I have also emailed them with a support question and they responded quickly and were helpful. They now fit great, they just needed to be worn in water for a day or with a pair of socks for a day. like everyone says, these run small, so even though i would normally buy large for comfort, i got these in the biggest size, 3X, expecting long and baggy. As for the reviews saying they are flimsy, that has not been my experience at all. The installation instructions were fine, had no problem figuring out what to do. I wear a 7 1/2 and ordered the 7-8 medium size, my toes were pushing against the end uncomfortably at first. One to many exchanges and you could be banned.