While recording music， artists put a great deal of effort into perfecting every detail. However， people may lose a lot of detail and finesse when using the common pair of earphones， and thus they are not able to enjoy the perfect sound effects created by the music and the optimum quality of music is lost. Product Specifications: Driver Type: dynamic Plug type: 3.5mm Driver diameter: 40mm Frequency response: 15~22，000 Hz Sensitivity at 1 KHz 1mW: 108dB Input impedance: 16? Max power: 50mW Wireless mode: Bluetooth 4.0 Microphone: yes Battery power: Rechargeable 700mAh Power standby: 1000 hours Music playing time: over 20 hours Audio cable length: 1.2M Weight: 170g Product dimension(L x W x H): 182*170*65mm