Mini HiFi Headphone AmplifierIt is Delicate, Compact, Lightweight, and Portable that it can be Carry Conveniently 3.5mm AUX Input and Output3.5mm AUX Input and Output, SNR>120Db and THD+N 0.0003%, Make it Possibility to Output not just Louder Sound, but a Sharper and More Real Stereo Sound without Distortion Aluminum Matte SurfaceFashion Design Provides You a Comfortable Handheld Feeling While the Aluminum Matte Surface Makes it Durable um BatteryIt Adopts a Rechargeable Battery, Which Allows it to Stay Working About 12 Hours Wide CompacityIt can Remarkably Compatible with a Various of Digital Devices, Such as MP3 MP4 Mobile Phone Computer (Tips: It is not recommended to use while charging, because current disturbance will occur when charging, Which may lead to noise)