1. Widely Compatible: This headphone amplifier is suitable for most 3.5mm jack headphones and for Quiet Comfort 25 (QC25) headphones, for Quiet Comfort 35 II (QC35 II) headphones and for Quiet Comfort 45 (QC45) headphones.2. 96KHz 24bit sampling frequency: This external USB sound card can turn any PC or laptop into a powerful source. The DAC sampling frequency supports 96kHz/24bit.3. USB to 3.5mm Adapter: This USB adapter uses a USB to 3.5mm jack adapter. Connect headphones with a 3.5mm jack to the USB interface of a PC or laptop.4. USB Volume Control: This external sound card features a knob that allows you to adjust the main volume of your PC or laptop, including the volume of all applications currently in use.5. Microphone Monitoring: This headphone amplifier features microphone monitoring so you can hear your own voice through the headset. Press the button on the front of the controller to switch four monitoring levels including Off, Low, Medium and High.Specification:Item Type: Headphone AmplifierMaterial: ABS Application: Suitable for most 3.5mm jack headphones and for Quiet Comfort 25 (QC25) headphones, for Quiet Comfort 35 II (QC35 II) headphones, for Quiet Comfort 45 (QC45) headphones.USB -Protocol: USB2.0Operating voltage: DC 5V ± 0.3VWorking current: DAC decoding SNR: 97 dBDAC sampling frequency: 96 kHz/24 bit Headphone driver capacity: 16 to 150 ΩHardware equalizer: bass and treble boostDevice jack: 3.5mmSupported transmission parameters: 8K, 16K, 22.05K, 32K, 44.1K , 48K, 88.2K, 96KSupport Bit Depth: 16/24 BitCable Length: Approx. 2.5 meters / 8.2 feet (manual measurement, slight errors may occur)Use:Plug and