Audio-Technica ATH-M50S Professional Studio Monitor Headphones - with Straight Cable with FiiO E6 Headphone Amplifier Audio-Technica ATH-M50S Professional Studio Monitor Headphones - with Straight Cable + BONUS FiiO E6 Headphone Amplifier. Exceptional audio quality for professional monitoring and mixing Collapsible design ideal for easy portability and convenient storage Adjustable padded headband for comfort during long mixing or recording sessions. Frequency Response: 15 - 28000 Hz. Cable Length: 3.50 M BONUS ($25 Value) FiiO E6 Headphone Amplifier &lt;&gt; For high impedance or low sensitivity Hi-fi headphones ButterflyPhoto is a Authorized Audio-Technica Dealer