This USB telephone headset is made of , which can withstand use. Features the PU material, which has high durability, not easy to deform. Fine workmanship, ensures practicality. This USB telephone headset will make easier and smoother. Features -Color:Black -Material:PU -Size:15.00X14.00X5.00cm/5.89X5.50X1.97in Interface type: USB 2.0 connector Speaker diameter: 30mm Speaker impedance: 32ohm Speaker frequency response: 20Hz - 20KHz Speaker sensitivity: 115dB Rated output power: 41MW Large output power: 84MW Noise level: <=-78 Dynamic range: >=78 Distortion rate : <=0.1% Stereo crosstalk: <=-52 Microphone sensitivity: -52dB Microphone directivity: omnidirectional Microphone impedance: <=2.2Kohms Microphone frequency response: 50Hz - 15KHz Headphone wire length: 2m - Over ear wearing protection, noise isolation, , comfortable to wear. - The earmuffs are made of high grade PU material, and the earmuffs are filled with slow-rebound sponge, which is soft and comfortable. - Easy to use, USB powered and input, no need to install driver yourself, plug and play. - The earphone adopts one-side incoming line, which avoids the trouble of line miscellaneous. - Special design and it is in fine craftsmanship. It is the best replacement for your old, broken one. Package list: 4 x telephone headset