Koss KDE250 headphones feature three sets of ear clips adjustable to just the right height for a comfortable, personalized fit by simply rotating the custom fit dial. This dual element, side-firing headphone allows listeners to experience the full scale of the musical sound stage in high fidelity while being incredibly active. Koss also designed a unique hinge mechanism to accommodate the intrinsic shape of the ear. This hinge plate allows the listener to modify the angle of the transducer as it enters the ear canal, improving comfort and isolation while enhancing transparency and sound quality. Koss developed the KDE250 headphones with a pair of dynamic transducers that mount at a perpendicular angle, for greater efficiency and accuracy across the entire musical spectrum to levels that exceed audibility. The larger 20 mm transducer is low frequency dominant and ported, while the 13 mm transducer focuses on mid and upper frequencies in a side-firing angle.