Overview Designed to combine the evenly-dispersed sonic detail of planar magnetic drivers with the tonal heft of more traditional, moving-coil diaphragms, the Ella from Blue comprise a pair of sealed, over-ear headphones. They sport 50 x 50mm planar magnetic drivers to deliver a transparent, detailed sound which, unlike dynamic-driver headphones, will not distort in certain frequency ranges as you crank the volume. Moreover, with an on-board 250mW amplifier, you will be able to achieve the level you'd expect out of your headphones in a manner that preserves tonal integrity; this is especially useful when pairing these headphones with MP3 players, smartphones, and iOS devices. These headphones come with two detachable cables, one with iOS controls and a microphone for smartphone communication and Siri control, the other providing an audio connection to any device without the bells and whistles of mobile communication. Also included are a soft case and a 3.5mm to 1/4" adapter. Features: 50 x 50mm Planar Magnetic Drivers Sealed, Sound-Isolating Over-Ear Design Built-In Headphone Amplifier 20 Hz to 20 kHz Frequency Response Detachable Audio Cable Detachable Audio Cable with iOS Controls Included Case & 3.5mm to 1/4" Adapter Rechargeable battery provides up to 12 hours of playtime; Ella continues to play music even when battery has no charge