The flat section fits my air pods pro and charges them through their case. Do not buy this product. If you are, get it. I liked it at first because it was so lite, but after playing with it constantly I realized it was absorbing ball contact. These Koss headphones were only 3 bucks more than buying new foam covers so I thought Ill just buy a new pair of headphones. It actually has exceeded my expectations and my wife loves it. No ‘whistle’ at 50Mph or slower on surface roads. I tested it out with my 27 lb. The bass is good if you have the right EQ settings on your audio player. Llegó a tiempo y sin lo que esperaba pero no se pueden configurar en el software y eso bueno pues es una desventaja