Koss Ksc/10 Portable Stereophonefoam Ear Cushions Foam ear cushions for open, hear-through sound. Durable plastic headband adjusts for best fit Frequency Response: 40-20,000Hz, 32 Ohms Impedance, Open Ear Cushions, 3.5mm Plug Straight Dual Entry 4-Foot Cord Dynamic Element Design for Deep Bass Performance