【Audio cable 3.5mm input /3.5mm output】Designed with convenience in mind, the Hi-Fi Headphone Amplifier features a 3.5mm audio cable input and output, allowing for seamless connectivity with a wide range of devices. Its high-quality audio performance ensures crystal-clear sound and minimal distortion, delivering a truly immersive listening experience 【Easy to Carry】The amplifier's compact portable design allows you to easily take music with you whether you're traveling, working, or just relaxing at home. 【Built-in power-bank】The Hi-Fi Headphone Amplifier has a 3000-mah lith-ium-batt-ery with a maximum output of 5V1A and can fully charge a phone at a time.And play music for up to 30 hours