PLANTRONICS Vista M22 Amplifier with SupraPlus H251 Voice Tube Headset Ideal for professionalsparticularly VoIP users Delivers precise levels of listening comfort, sophisticated hearing protection, and superior audio performance The audio processor includes near-universal compatibility with single and multi-line telephones, as well as ergonomically designed volume, headset/handset and mute controls H251 offers all-day wearing comfort and reliability, with Enhanced audio for greater listening accuracy Clean and soft ear cushion and voice tube for all-day comfort