1. The button on the left side is to turn on the sidetone function of the earphones, that is, the ambient sound is transmitted to the earphones through the microphone, and your own voice will also be transmitted to the earphones.2. Computer Controller: By turning the top knob on the desktop volume controller, you can adjust the master volume, including the volume of any application currently in use.3. Microphone monitoring: With the microphone monitoring function, you can hear your own voice through the headset. Press the button on the front of the controller to cycle through four monitoring levels, Off, Low, Medium and High4. Suggestion: When using active or passive noise-cancelling headphones, make sure that you can receive reminders such as phone calls or ringtones. If you use them outdoors, you must make sure that the environment is safe5. Function: Optimize sound6. Device jack: 3.5mm7. USB protocol: fully compatible with USB2.08. Working voltage: DC 5V9. Working current: less than 20mA10. DAC decoding SNR: 97dB11. DAC sampling rate: 96KHz/24bit12. Headphone drive capacity: 16-150 ohms13. Hardware equalizer: bass and treble boost14. Support audio bit depth: 16/24bits15. Support broadcast parameters: 8K/16K/22.05K/32K/44.1K/48K/88.2K/96K16. Weight: 225gSpecification: Package Weight One Package Weight 0.25kgs / 0.56lb One Package Size 6cm * 11cm * 8cm / 2.36inch * 4.33inch * 3.15inch Qty per Carton 150 Carton Weight 38.00kgs / 83.77lb Carton Size 60cm * 33cm * 40cm / 23.62inch * 12.99inch * 15.75inch Loading Container 20GP: 336 cartons * 150 pcs = 50400 pcs40HQ: 781 cartons * 150 pcs = 117150 pcs