I can't afford zero-possibility-of-break-down products. The cost of making sure that no product ever fails would be enormous. However, Aftershokz is pretty close.
I use my Aftershokz Titanium Headphones daily. I ride a bicycle to work and need to be able to hear the traffic all around. I use my riding time to listen to audible books. I knock out about two novels a month just be riding to work. The Aftershokz Titanium Headphones finally quit working and would not connect to my iPhone. I went to their website and tried their solutions. None of the worked. Customer service contacted me promptly after I sent a message to the company. They sent a return label at their expense so I could send the headphones back. (They come with a two year warranty!) They replaced the headphones without any grief!
The product is great for audible books and talking on the cell. Customer service has been stellar. I highly recommend their products and customer service.