Audio-Technica ATH-CKR100iS In-Ear Headphones - BlackFeaturing dual phase push pull drivers, the ATH CKR100iS in ear headphones deliver high resolution audio thats true to the original sound. The unique push pull system incorporates two facing 13 mm drivers that generate phase aligned audio signals that are mixed to compensate for each drivers inefficiencies, while providing an equal and tailored response without artificial coloration. By reducing intermodulation distortion, the push pull drivers