The Coloud Twelve headphone is a thoroughly tested headphone model proven to work fantastically. It’s a one-size-fits all headphone with a neutral sound and a snug fit. Driver Unit 40 mm Power Drivers Frequency Range 20 Hz~20001 Hz Impedance 32 ohms 1KHz Sensitivity 120 dB Max Input Power 100 mW Plug 3.5 mm Coil Cord 1.2 m Premium replacement warranty 1 year