Driver unit·ª dia.40mm Frequency response·ª 20-20khz Impedance·ª 32 ohm Sensitivity ·ª 105db, 111db (at 1 khz) Noise reduction level f¦13db at 300hz Plug·ª ¦ª3.5mm, with ¦ª6.3mm adapter Battery ·ª 1pcs aaa bettery We combine active noise cancellation with style. Comfort and sound quality to create a full, rich sound anywhere you use them. Thanks to the soft ear cushions and lightweight design you'll enjoy superior comfort for hours of listening pleasure. Plus, you'll experience optimal sound quality and speech clarity even at lower volumes, easily adjusted by the in-line volume control. Requires one aaa battery (not included) .It is compatible with all ipod, mp3, cd, dvd players, computers, in-flight and home entertainment systems