Detailed offer Description 1.)The head band is foldable,and the whole headphone can be folded to be as small as a pair of glasses in size; 2.)Headphone receivers are made from well selected natural wood,so it is light and environmentally-friendly; 3.)High components solution to the headphone to strengthen its performance and better its sound quality,components are as below:Speaker: Neodymium Diameter 40mm ; Impedance: 32 ohm +/-15%; SPL at 100 Hz: 105dB+/-3dB;Frequency Range: 15-22K Hz; Cord Length: TPU/OFC wire,1.8M; Plug: 3.5mm plug; Normal Input Power:5mw.