The Koss Plug has revolutionized the world of in-ear headphones. As the first headphone of its kind, this noise-isolating in-ear headphone offers accurate acoustic reproduction and isolation typically found only in high-end closed-back headphones. A dynamic element located just outside the ear is connected to a tubular port structure, which is fitted with a soft, stretchable cushion. The soft foam cushion expands, providing a personalized comfort for every listening experience. Additionally, it enhances isolation by blocking out ambient noise and improving the clarity of deep bass and treble. Combine the Koss Plug with your favorite music, and it becomes the ultimate accessory for on-the-go listening.