Audio-Technica ATH-CKR7 SonicPro In-Ear Headphones Large, proprietary 14 mm drivers deliver ultra-expressive, high-resolution audio Unique hybrid housings of stainless steel and aluminum greatly reduce unwanted resonance for crisp mid- and high-range reproduction. Stainless steel stabilizers absorb unwanted vibration to prevent audio distortion. Dual acoustic resisters improve frequency response Includes silicone ear tips (XS/S/M/L) and protective pouch