Feature: 1. Metal Material: Headphone amplifier is made of metal material, strong and durable, with a non slip pad at the bottom for stability. 2. 4 Channel Stereo Headphone Amplifiers: 4 channel distribution system allows up to 4 person to listen and play at the same time, with excellent sound quality. 3. Independent Adjusting Knob: Individual volume controls allow each listener to determine their own volume through a dedicated output volume control knob. 4. Low Noise: Enjoy a low noise monitor distribution and music system. The ultra compact stereo headphone amplifier is easy to carry and can be used anytime, anywhere. 5. Widely Used: Ultra compact headphone amplifier system is for studio and stage applications, outdoor performance, mini concert, karaoke, conference speech. Specification: Item Type: Stereo audio amplifier Material: Metal Weight: Approx. 332g / 11.7oz. Package List: 1 x Headphone Amplifier 1 x Adapter1 x Instruction Manual