This is a portable HiFi headphone amplifier with Bluetooth connectivity and volume control. It supports 16-600Ω impedance earphones and has a built-in high-capacity battery. The amplifier also features a 3.5mm input port, a 3.5mm headphone port, and a Type-C charging port. It is made of aluminum alloy and comes with a user manual, a 3.5mm audio cable, and a charging cable. The amplifier is suitable for use with headphones, smartphones, and gaming consoles, and is designed to improve the sound quality and volume of your audio.