Specifications: This headphone amplifier can help players with low thrust to drive headphones better. It can also help headphones with high impedance or low sensitivity to be better driven This amplifier can play a certain tuning role. It can reduce the bottom noise, turn the volume knob to the maximum (when mute), the bottom noise is basically inaudible. The amplifier can Increase the voice, enhance the sense of three-dimensionality and depth. Item Name: HiFi Headphone Amplifier Audio Input And Output Interface: 3.5mm Stereo Interface Battery Charging Interface: Micro USB Interface Charging Current: 1A Battery Capacity: 2000mAh Use Time: More Than 8 Hours Internal Voltage Of The Amp: and plusmn;7.5V Signal To Noise Ratio: (Snr) and gt;100db Distortion: (THD+N)0.0003 Output Power (Thrust): 40MW Suitable for Headphones (Earplugs): Impedance 16 - 150 Features: Easy to Use, Fine Workmanship, Portable Size: 9.8cm x 6cm x 1.5cm/3.86 and quot; x 2.36 and quot; x 0.59 and quot; (Approx.) Notes: Due to the light and screen setting difference, the item and 39;s color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Host 1 x USB Power Cord 1 x Headphone Cable 1 x User Manual Easy to Use, Fine Workmanship, Portable Easy to Use, Fine Workmanship, Portable Easy to Use, Fine Workmanship, Portable Easy to Use, Fine Workmanship, Portable HiFi Headphone Amplifier