This is a portable DAC headphone amplifier from Kinera. It supports Hi-Res audio. It is equipped with the ESS ES9039Q2M high-performance DAC chip. I purchased two. I am selling one. I only opened it to confirm normal operation. Specifications: ・Equipped with the low-power, high-performance ESS Sabre DAC chip "ES9039Q2m" ・Achieves high performance through a meticulous power circuit design ・High-speed processing USB interface chip ・Supports UAC1.0, also suitable for gaming use ・Size: 52x23x14mm ・Weight: 16g ・Ports: 4.4mm balanced / 3.5mm single-ended ・Input port: USB Type-C ・Gain switch function (up to 4vrms Balanced) ・Output power: 250mW (32Ω) single 480mW (32Ω) balanced Thank you.