Skull Candy says this it its "Stay Aware Feature", but that might just be their marketing spin for not having great fit & multiple tip options. Have had a pair of original crocs for years. The control buttons are on the right ear wire. I ordered one black and one flowered and love them both! I get tired of trying to find him cheap ones that are big enough because he wears them out so quickly. They are snug around my foot, but not tight or uncomfortable, and I feel much more confident walking in them. Some are useful but many many ads. I get there isnt much if any thread work in this product for a seam anyway but the weld or whatever they tried really did not equal the price they are asking. The white light as a strobe is great for alerting walkers who are consumed with their phones! I?m 5?8? and weigh about 145lbs and I ordered a M which was the perfect size.