Features:1. Suitable for call centers. Excellent sound quality， light weight and durable 2. Noise canceling， can reduce background noise 3. Hearing on both left and right sides and microphone can be worn on either left or right ear 4. Very comfortable ear pad， comfortable for all day use 5. Adjustable headband， acoustic shock protection circuit Model number: XD600-03Frequency range(Hz): 20¡«20KHzFit Design: over the earFeature: microphoneColor: blackInterface: 4PIN RJ11 telephone crystal head 1. WireCable length: maximum length: about 2mLine breaking strength: not less than 10LbsTensile test: connecting portion of wire and pins， the wire and earphone case should be connected reliably， can endure 1.5Kg pulling force， no loose or fall off and can work normallyCore structure: (8 / 0.1 + 250D) ¡Á 4The total impedance: not more than 0.3¦¸ per meter2. Speaker specificationType: moving-coil speakerImpedance: 150¦¸Sensitivity: 118 ¡À 5dB at 20¦ÌPa = 0db， 1KHzCenter frequency: 800 ¡À 50HzRated input power: 5mWMaximum input power: 30mW3. MicrophoneType: electret condenser microphoneImpedance: 2.2KSensitivity: -50 ¡À 3dB at 20¦ÌPa = 0db， 1KHzFrequency response: 30 ~ 16KHz 1 x Telephone headsetIn original package