audio-technica CKR Series ATH-CKS550 BK Used, operation confirmed. Some scratches and signs of use are present. Body only. Product Specifications Model Number: ATH-CKS550 BK Type: Dynamic Driver: φ9.8mm Output Sound Pressure Level: 105dB/mW Frequency Response: 5～24,000Hz Maximum Input: 100mW Impedance: 16Ω Weight (excluding cord): Approximately 7.5g Plug: φ3.5mm gold-plated stereo mini (L-shaped) Cord: 1.2m (Y-type) Color: Black Equipped with a newly developed φ9.8mm "DUAL MAGNETIC-FIELD DRIVER". New structure that enhances the driving force of the driver for overwhelming deep bass reproduction.