Features 1、Innovative tone balancing technique: Restore the voice clearly. 2、Broadband HD Speakers: Optimize the sound effects of audio segments to fully display the perfect sound quality of human voices. 3、Professional microphone noise cancelling technology: Can block 99% background noise. 4、International standard hearing protection: Effective prevention of sudden high-decibel sound on the ear damage. 5、Slow rebound stainless steel bars: Adjustable length, suitable for different head shapes. Specification Features: Innovative tone balancing technique: Restore the voice clearly. Broadband HD Speakers: Optimize the sound effects of audio segments to fully display the perfect sound quality of human voices. Professional microphone noise cancelling technology: Can block 99% background noise. International standard hearing protection: Effective prevention of sudden high-decibel sound on the ear damage. Slow rebound stainless steel bars: Adjustable length, suitable for different head shapes. Super soft and slow rebound earmuffs: Comfortable to wear, suitable for long-time wearing. Specification: Name: Operator headset noise canceling headphones Model: A26-RJ Weight: approx. 92g Size: approx. 15.3 * 13.6 * 5.2cm / 6 * 5.4 * 2inch Noise reduction function: double noise reduction technology Microphone: Single-sided noise reduction microphone Interface: RJ11 crystal head Microphone impedance: 2.2K / Ω Microphone sensitivity: -38dB ± 3dB Wire control function: 100-4800HZ Speaker impedance: 150Ω Speaker sensitivity: 116dB ± 3dB Package List: Telephone Headset * 1