This is a FitBit product, so I would advise everyone to stay away. I have had 4 of these the last year and the build quality is terrible. You can not expect it to last more than three months with careful use.
The rubber edges are very exposed, so you risk destroying it by just taking off a sweater, and the problem only gets bigger after that. Picture:
Also, the holes you plug the other end in to are also a big design fail. They are just a strip of harder rubber to hold the pins, but the strip it self is held in place by the soft rubber, and the first and last hole barley has any soft rubber holding it in place as the strip ends there. This results in the harder rubber getting dragged out from the softer rubber. Pictures: