The K5 PRO is a mini stereo gaming DAC headphone amplifier with microphone, supporting usb Type-C,optical and coaxial digital inputs, 3.5mm headphone jack, and RCA outputs, suitable for most home audio systems. With treble and bass control, it can be used as a preamplifier or volume control for PC/Mac. Fosi Audio K5 PRO DAC ensures exquisite muslcallty, accurate and realistic phasing, and reproduction of the sound! Input : USB Type-C, Optical, Coaxial, Microphone Output : 3.5mm Headphone, RCA PC-USB supports input sampling rate: Up to 24Bit/96kHz Optical/Coaxial supports input sampling rate: Up to 24Bit/192kHz RCA Output Level: 2V Powe Supply:5V Power Input Interface: USB Type-C THD: Less than 0.003% SNR: 110dB Frequency response: 20Hz-20kHz (3dB) PC-USB support operating system: XP/W7/W8/W10/MAC/linux Distortion: 0.001%; Amp output maximum power: 1000mw/16, 500mw/ 32, 300mw/64, 150mw/128, 80mw/300 Headphone matching impedance: 16-300 Colour:dark gray Material:Metal Package Contents: 1 x Headphone Amplifier Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.