The Koss EQP1 Technology Stereophone in Case has a built-in amplified 3-band equalizer which delivers frequency response and acoustic contouring and allows the listener to customize their listening experience The Stereophone neodymium iron boron magnet structures deliver unmatched bass performance. The Stereophone also has a titanium-coated dynamic element for full frequency response. The unique Sportclip design fits around the ear to eliminate the headband for ultra lightweight comfort and portability. Three independent slide controls allow incremental adjustment of center EQ frequencies.