More microphones result in better sound quality and enable the device to filter out background noise.
Parrot Zik Sport: 8
16. has an on-ear form
This device comfortably rests on top of your outer ears. As it doesn't block out everything from the outside world, it's preferred in places like office environments and recommended for outdoor activities.
Bang & Olufsen Beoplay H2
Sol Republic Tracks HD
22% have it
17. Weather sealed
Device is protected with extra seals to prevent failures due to any kind of weather.