Skullcandy FMJ's stand for Full Metal Jacket. That's a metal case with some precision engineering that contains some high grade components that deliver great sound. Despite its outstanding frequency separation, crystal clear mids and highs, and enough bass to rock a mule's ass to the moon, the FMJ is not officially the favorite ear bud of everyone on Earth. Technically, the Skullcandy FMJ is only the official favorite bud of people with ears and personal style. Suitable for iPhone and Blackberry Curve. Skullcandy's iPhone FMJ lets you and your iPhone rock together AND talk together. We don't care who you talk with. SPECIFICATIONS With build In-Mic 11mm speaker Frequency range: 16 Hz – 20K Hz Impedance: 16 ohms Max input power: 5mW Cable type: Aluminum foil Cable length: 1.1 M Plug type: 3.5mm gold plated Please select from the available color options below: