The HA-F91 is the ear bud headphone constructed with elastomer, a new material that promises a comfortable fit. The HA-F91 Stereo Ear Buds let you get the most out of your Music while you're on the move. No foam needed for these buds - it's designed to reduce ear stress and play full tones. They also have inline volume control so you can ajust your music volume without having to touch your MP3 player or any audio device being used.