The bigger and slightly heavier one is the Model O. Its purchase price is less than what wed pay to rent a phone from a meeting venue. I had a Apple iPad charger I used for fast charging and regular individual apple USB adapters for the rest of my devices. Insert now perfect insoleNow these shoes fit extremely well, and are much more comfortable. Make sure to order a size up as they are very narrow, but the tight fit helps to improve that feeling of responsiveness and agility even further, so dont let the tightness turn you off. 5 fits well and my feet feel very comfortable width wise. The distance in coverage is given or take the same as far as feet away from the device as compared to the previous version. Now if only I could stop losing individual earbuds lol. )Would be great if Bose had a solid new version - based on reviews, none of the wireless are as good for calls (microphone /bluetooth audio cant compete with a wired connection). I also like the way the they made the aux jack right angled.