The Koss KSS10 are Behind-the-Head headphones designed for comfort and affordability. Its light weight and foam ear pads make them comfortable to wear for long periods of time. The behind-the-head design design keeps them from interfering with hats and helmets, and allows them to fit all head sizes. The foam ear pads also give them an open hear-through sound allowing the user to hear sounds around him, making them ideal for workouts, navigating around the city or in the office. The 4 foot single entry cord has a standard 3.5mm jack. The frequency response of these headphones is 40-20,00 Hz.