Feature:1. Noise Cancelling Traffic Headset: Built in HD microphone, which can be twisted at will to make your voice clear. Provides clear dialogue even in noisy environments. Less noise and clearer sound.2. Comfort Wearing: Telephone headset provides an ultra lightweight wearing experience. Soft ear pads and flexible headband don't put any burden on your ears. You can concentrate on your conversation.3. Support Speaker Volume Adjustment: Office phone headset plug and play, no driver required, supports speaker volume adjustment, and is easy to use, meet your daily needs.4. Sturdy Structure: RJ9 Double sided headset is designed with sturdy construction and materials to ensure super performance and make them durable. Long cable provides flexibility on the move.5. Wide Compatibility: Phone headset is compatible with devices with RJ9 headphone plug. Ideal for home offices, call centers, telemarketing, customer service, conference calls, and more.How to Use:Plug and PlaySpecification:Item Type: RJ9 Phone HeadsetMaterial: ABSModel: H390D-RJ9-VAColour: BlackType: BinauralPlug: RJ9Function: Call, Speaker Volume Adjustment Applicable Scope: Compatible with devices with RJ9 headphone plugSpeaker Parameters:Sensitivity: 105±3dB (at 178mV 1KHz)Voice Coil Impedance: 150±15Ω (at 1KHZ)Frequency: 100Hz-10KHzDistortion: ≤5% (at 178mV 1KHZ)Microphone Parameters:Directivity: UnidirectionalSensitivity: -40±2dB (2.0V, 2.2KΩ, 1KHz)Distortion: ≤5% (at 4.5V 2.2KΩ 1KHZ)Frequency: 200Hz-6KHzCurrent Consumption: 100-500υA Package List:1 xRJ9 Phone Headset