A standard 3.5mm male connector is suitable for use with all MP3 players and computer sound cards.
Able Planet Clear Harmony Sound SI1000B
Philips Sports Earhook Headset SHQ3017/28
87% have it
20. has an in-ear form
The in-ear device is ultracompact and lightweight, with little or no interference with earrings, spectacles, hats, or hairstyles. It is inserted in the ear canal itself and blocks out a lot of environmental noise. It has stronger bass tones and is unlikely to fall out of the ear.