Sennheiser HD448 Closed Circumaural Hi-Fi Headphone (Discontinued by Manufacturer) High quality closed back around the ear headphones Advanced acoustic transducers with a specially tuned frequency response Unique leatherette ear pad design blocks outside noise for safer, critical listening Gold plated 1/8" headphone plug (1/4" adapter included) 2 year warranty, Input Impedance - 32 ohms