Description of Skullcandy Full Metal Jacket 11mm Headphones With a streamlined metal alloy casing and your choice of 9mm or 11mm speakers, the Skullcandy Full Metal Jacket is fully loaded. FMJ comes equipped with a custom EVA carrying case and three sizes of ear gel sleeves. Features: Speaker diameter: 11 mm Frequency response: 16 Nz-20z Hz Impedance: 16 ohms Max input power: 5 mW Cable type: TPE Cable length: 1.4 m Plug type: 3.5 mm gold plated Weight: 13 g