Addasound Crystal 2701 Noise Cancelling Headset Monaural, Quick Disconnect Cable (CRYSTAL-SR2701) Noise cancelling microphone blocks 80 percent of background noise and highlights your voice. Wideband audio processing ensures natural sound transmission. Easily compatible with different telephones and PC via varieties of Quick Disconnect QD cords. Maximum volume control protects your hearing under intensive usage. Ultra lightweight design for all day comfort. Adjustable headband to be most suitable for your wearing. Only environmentally friendly materials are used for our products.