Fangrui Product Details 1. Vt200d Double Ears Telephone Headset Operator Headset With Mic,spec: Crystal Head With Tuning 2. Up And Down Retractable Headband, Adapt To A Variety Of Head Shape 3. Using Soft Microphone Cotton, Can Effectively Reduce The Background Noise, Talk More High Definition And More Comfortable. 4. The Hose Has Resistance To Bending, You Can Adjust The Hose To The Position You Think Comfortable. 5. Comfortable Ear Cushions, Fine Texture, Removable And Replaceable 6. Durable And Resistant To Swing Headset Cable, Pure Copper Impedance Is Low, The Sound Is Not Affected 7. 5 Kinds Of Plug Design, Compatible With A Variety Of Devices 8. Speaker Parameters: 9. Size: Diameter 28mm 10. Distortion: Less Than 0. 11. Impedance: 150 Ohms 12. Sensitivity: 118db+-3db 13. Frequency Response: 200-4000hz 14. Microphone Parameters: 15. Microphone: Omnidirectional 16. Signal-to-noise Ratio: Greater Than Or Equal To 52db 17. Distortion: Less Than 0. 18. Impedance: 2200 Ohms 19. Sensitivity: -34db 20. Frequency Response: 100-3000hz