The m12e vista adapter is the premium universal adapter that connects your headset to your phone and can be used with a wide range of plantronics headsets it is compatible with the majority of business telephones and features plantronics call clarity and soundguard plus technologies which enhance the quality of the call and ensures that what the user hears is kept at a comfortable level the vista has a headsethandset switch full volume controls and mute button unlike the standard m12 the