Feature: 1. Wide Compatibility: This headphone amplifier supports a wide range of high impedance 16‑300Ω headphones. With 3.5mm AUX input and output, it ensures clear quality audio and eliminates noise, allowing you to enjoy premium sound. 2. 2 Stage Gain Switch: This headphone amp enhances the signal from the input to the amplifier circuit, enabling optimal performance of the headphones. It not only outputs louder sound but also delivers clearer and more stereo sound without distortion. 3. Rechargeable Lithium Battery: Equipped with a 1500mAH rechargeable lithium battery, this headphone amplifier can work for over 8 hours. Additionally, it features a volume control knob for convenient adjustment of the volume. 4. Portable and Lightweight: Designed to be portable and lightweight, this headphone amplifier allows you to enjoy music anytime, anywhere. Its sturdy aluminum alloy casing ensures durability for long term use. 5. Wide Compatibility: This amplifier is compatible with various digital devices such as MP3, MP4, Phone, computers, CD players, personal media players, and more, making it versatile for different audio setups. Specification: Item Type: Audio Amplifier Material: ABS Built in Lithium Polymer Battery: 1500 mAh SNR: 120dB Output Power: 2000mW, 16Ω. Package List: 1 x Audio Amplifier 1 x USB Cable 1 x Audio Cable 1 x User Manual