Item Type: Headphone Amplifier Material: Metal Weight: Approx. 315g / 11.1oz Voltage: AC 100-240V 50Hz 60Hz Metal Material: Headphone amplifier is made of metal material, strong and durable, with an ultra-compact design for easy portability. 4-Channel Stereo Headphone Amplifiers: Features 4 headphone output channels and 1 input channel, delivering excellent sound quality. Independent Control: The volume of each output channel can be controlled independently, providing optimal sound quality for each connected headphone even at maximum volume. Low Noise: Utilizes an ultra-low-noise 4580 operational amplifier to ensure superior audio performance. Offers low-noise signal distribution for monitoring and music systems. Widely Used: The ultra-compact headphone amplifier is suitable for studio and stage applications, outdoor performances, mini concerts, karaoke, and conference speaking.