The Endurance PEAK II adjusts to you, not the other way around. The bendable wire on the ear hook lets you adjust the headphone to your size and comfort level. Also, you can stay focused on the task at hand with music that starts and stops when you do and controls intuitive enough to almost read your mind make it easy to stay in the groove.
It doesn't matter which headphone you take out of the case first. You can take calls, adjust volume, or use your voice assistant on either ear, so you can stay flexible and never mess with your momentum.
Go ahead and get as wet as you want. Whether it's rain or pure, honest sweat, no worries for the Peak II.