Have been using this for about two months perfectly, every day I make 25-50 calls. The case uses a USB A to USB C cable to connect to a standard Low Voltage (5V 1 A) USB wall charger. They appear to be sturdy. I returned them and reordered a size 1. But its something worth mentioning. Bass extension is good and clear. As per the reviews, I ordered a size up from my regular, and I still find it a little too small. There music is loud and when having both was buds in its loud and clear. I was very excited when I received my waist trainer yesterday. Die Kombination macht es schon sehr ruhig.