Koss IL200 KTC interlocking in-ear headphones features a truly original design coupled with a unique material to form a perfect harmony. The interlocking in-ear headphones utilizes an ingenious patented design for easy on-the-go storage without sacrificing richly delivered audio delivered through performance tuned 9 mm drivers. Koss Touch Control (KTC) remote and microphone technology, made for iPhone, iPad and iPod, gives listeners more control in fewer steps. Listeners are now able to stay connected, shuffle songs and adjust the volume with the simple flick of a switch. The frame of the new interlocking in-ear headphones is constructed from highly polished metal and surrounded by flexible, soft-touch material. This innovative material doubles as a soundproofing coat, intended to deaden any unwanted distractions, that allows the listener's focus to remain on the crystal clean highs and crisp lows -while staying inside the music they love. The interlocking design allows the two in-ear headphones to easily nestle together for simple, tangle-free storage. With its durable metal structure the IL200 KTC in-ear headphones will eliminate the stress of trying to undo the impossible knots that always seem to form when storing in-ear headphones or earbuds. Koss has created the perfect harmony between form and function, so that all you have to worry about is the music. Features: Original interlocking design Koss Touch Control (KTC) remote and microphone technology, made for iPhone, iPad and iPod Durable metal structure Includes three sizes of silicone ear cushions Straight, dual entry 4ft cord Technical specs: Frequency Response - 15 - 20,000 Hz Impedance - 16 Ohms Sensitivity - 100 dB SPL Cord - Straight, Single Entry, 4ft with 3.5 mm plug Dimensions: 2.875 L x 1.5 W x 5.5 H; 0.01 lbs.