The Koss KSC17 are Behind-the-Head headphones designed for a user on the go looking for a well priced portable set of headphones. Its lightweight 2 ounce and fully collapsible design make it ideal to be packed into a gym bag or briefcase. The adjustable headband accomodates all head shapes, and will not interfere with hats or helmets. Dynamic elements of the KSC17 are contructed with mylar to give a frequency response from 40-20,000 Hz with minimal mechanical distortion. Neodymium iron boron rare earth magnet gives them higher output volumes, even from low-voltage portable devices. The included foam earpads allow users to still hear the world around them, making them ideal for work-outs, navigating the city or use at the office. The volume adjustment on the cord makes volume control easy, especially if the portable device being used is stored out of easy reach. The KSC17 has a 4 foot single entry cord, with L-shaped standard 3.5mm (1/8") plug.