An L-shaped plug is better if the jack is on the left or right side of the device, so that the cable isn't bent, and is less likely to break when the device is in your pocket.
31% have it
16. travel bag is included
The device comes with its own special case or pouch, which is useful for safe transportation.
63% have it
17. has active noise canceling/noise reduction
This type of device allows you to listen at lower volume levels, causing less ear fatigue as you don't have to crank up the volume to overcome background noise. Ideal for plane rides and morning commutes.
12% have it
18. has a 3.5mm male connector
A standard 3.5mm male connector is suitable for use with all MP3 players and computer sound cards.
85% have it
19. 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.
23% have it
20. diaphragm size
The diaphragm moves air back and forth to create sound. The bigger the diaphragm, the more bass it can produce.
Oppo PM-1: 85mm
21. has an open-back design
The device is designed in a way that allows sound to go out through the back of the ear cups, which usually have vents or perforations. This design provides very natural and accurate sound.