Feature:1. Noise Cancelling: Telephone headset with flexible high definition microphone for large, clear sound. Less noise, even in noisy environments, provides clear conversations.2. All Day Comfort: Phone headphone is ultra light, with soft ear cushions and a flexible headband that will not put any burden on your ears. Good for long conversations.3. Easy To Use: Wired telephone headset, standard RJ9 plug, plug and play, no driver required, easy to use, suitable for VOIP phones, landline, etc, to meet all your daily needs.4. Durable Structure: Unilateral headset has a sturdy structure and materials that ensure excellent performance and are durable. The long cable provides flexibility on the move.5. Compatible: The headset works with devices with an RJ9 headphone jack. Ideal for home, office, call center, telemarketing, customer service, conference calls and more.How to Use:Plug and play.Specification:Item Type: Telephone HeadsetMaterial: ABSModel: H390 RJ9Color: BlackType: Single EarPlug: RJ9Function: CallScope of Application: Compatible with Devices with RJ9 Headphone JackSpeaker Parameters:Sensitivity: 105±3dB (at 178mV 1kHz)Voice Coil Impedance: 150±15Ω (at 1kHz)Frequency Characteristics: 100Hz-10kHzDistortion: ≤5% (at 178mV 1kHz)Microphone Parameters:Directivity: Single PointSensitivity: -40±2dB (2.0V, 2.2KΩ, 1kHz)Distortion: ≤5% (at 4.5V 2.2KΩ 1kHz)Frequency Characteristics: 200Hz-6kHzCurrent Consumption: 100-500µA Package List:1 x Telephone Headset