KEY FEATURES OF PHILIPS SHS 390 HEADPHONE (BLACK) Wired, On-the-ear Headphone, Supra-aural, Closed Headphone, Behind-the-neck Design, 100 mW of Max Power Input, 40 mm Headphone Driver Units, 12 Hz - 22000 Hz Headphone Frequency Response, 24 ohm Headphone Impedance