iBasso SR1 High Definition Headphone

SpecificationsTransducer Type: dynamic Operating Principle: semi-open Frequency Response: 3Hz-40KHzSensitivity: 108dB at 1KHzImpedance: 22 ohmRated Power: 50mWT.H.D.: <1% (at 1kHz /1mW)Plug Size: 3.5mm gold-plated Cord Length : 1.8m