When I put it for the first time in my ears I feel it is a little bit lose and I have doubt that it will remain in my ears during my training, I tested it in the hard one while using my treadmill in high speed during my training for 30 minutes, it never moved and remain as it is which makes me happy, I also tested it during other training and it is really surprised me. After googling and trying various things we found out our Xbox Contoller needed a firmware update. Its also really finicky for what its plugged in to, which I suppose is to be expected but still annoying. It only comes with a USB charging card. The 4 was of course too big and the 12 was too small. I also love how the design makes the earpieces got in the ear canal directly, this makes me a person with a slightly deformed right ear real happy, there are not many earpieces that allow me to use both sides and enjoy the sounds so this a huge one for me. not too snug but just loose enough to let you slide in and out easily (giggity) and that you could wear them with socks if you so choose. I have wide feet so this won’t apply to everyone. My previous pair were wider. 11 kneepads or other makes (available on Amazon).