Plantronics M22 Vista Amplifier + EncorePro HW291N Headset COMBO Plantronics' M22 Amplifier features SoundGuard Plus technology that ensures loud tones are quickly reduced to more comfortable levels and ensures that the normal, human voice remains natural and unchanged, for face-to-face clarity of communication Plantronics Call Clarity technology uses electronic signal processing to reduce phone noise and maintain constant volume levels, as set by the user. This ensures all conversations are held at a comfortable and consistent level, regardless of the loudness of the incoming call. Plush leatherette earpads allow for hours of comfortable wearherweight design Reinforced, lightweight headband provides strength and durability. Elegant satin finish and featherweight design