Audio-Technica ATH-CKR10 SonicPro In-Ear Headphones Delivers amazing, high-resolution reproduction of the original sound World's first dual phase push-pull drivers (13 mm x 2, with pure iron yoke) provide extended frequency response by reducing intermodulation distortion Metal-coated titanium housings for a rigidity that greatly reduces unwanted vibration Stainless steel acoustic resister provides improved high-frequency response, while bass acoustic resister delivers accurate low-frequency response Includes silicone ear tips (XS/S/M/L) and protective carrying case