Specification: Item Type: Headphone Amplifier_x000D_Condition: 100% brand new_x000D_Model: XU09_x000D_Material: Aluminum alloy_x000D_Color: Black_x000D_Product Size: Approx. 9.8x6x1.5cm/3.9x2.4x0.6in_x000D_Audio Input/Output Interface: 3.5mm stereo interface_x000D_Battery Type: Polymer lithium battery_x000D_Battery Capacity: 2000mAH_x000D_Using Time: More than 8 hours_x000D_Internal Operating Voltage: 7.5V_x000D_SNR: >100dB_x000D_Distortion: (THD+N) 0.0003%_x000D_Charging Current: 1A_x000D_Battery Charging Interface: Micro USB_x000D_Charging Cable Interface: Micro USB to standard USB _x000D_Output Power: 40mW_x000D_Suitable Headphone Impedance: 16-150 Features: 1Full sound, gentle high frequency and heavy bass, bringing better music experience. 2Imported sealed stepping potentiometer with good rotating resistance and good hand feeling. 3The circuit is designed in arc to avoid current interference at the corner tip, thus simulating the grounding. 4Dynamic and noiseless, more suitable for rock, pure music and dance, helping drive the headset of high impedance or low sensitivity. 5High quality imported filter capacitor, adding sound field to enhance the stereo and depth. 6Adopt full repair program, mechanical welding, stable performance. Background noise is largely inaudible when the volume is turned to maximum (mute). PackageList: 1 x HiFiHeadphone Amplifier1 x Audio Cable1 x Charging Cable1 x User Manual