I wear them all the time. 75u and high in size keys have these break away bumps on the bottom of the cap. FOR SURE! I really like these wireless earbuds from UROK. The sparkles on the straps are coming off at an alarming rate, especially on the edges of the straps, but the good things outweigh this. I compared them to my other ultra boost and they are definitely authentic. This will save a lot of money in the long run. I have narrow feet, and I wear 40eu. In fairness to Ooma, I have two other Ooma devices at other locations and they have worked faithfully for several years. Setup is easy and now can work more effectively when at my home away from home.