Ideal for professionals particularly VoIP users. The Vista M22 amplifier delivers precise levels of listening comfort, sophisticated hearing protection, and superior audio performance. The Vista M22 includes Clearline audio to improve call quality in any environment, especially wideband VoIP. The amplifier includes near-universal compatibility with single and multi-line telephones, as well as ergonomically designed volume, headset/handset and mute controls. The Quick Disconnect feature between the amplifier and headset lets you move away from your phone without removing your headset or disconnecting the call. The Vista M22 comes complete with a lightweight 10-foot coil cord for freedom of movement at your desk.Amplifier is designed for use with traditional or wideband VoIP phone systems, including SupraPlus, Encore, Tristar, DuoPro, Duoset, and Mirage headsets. VoIP-ready Vista M22 amplifier is compatible with most office phones. Clearline audio technology enhances speech clarity and helps to reduce repeats, errors, and listening fatigue. Easy-to-use amplifier offers a one-button headset/handset selection plus controls for both incoming and outgoing volume. When used with wideband VoIP system, the Vista M22 delivers enhanced audio and more natural speech, reducing repeats, errors, and listener fatigue; reduces the level of incoming loud noises; and helps reduce echo associated with VoIP telephone technology. This universal headset audio processor uses two AA batteries (included). Amplifier includes a 10' coiled cable and Quick Disconnect, which lets you walk away from your phone without removing your headset.