Designed for telephone professionals using either traditional or VoIP phone systems, the Vista M22 amplifier delivers precise levels of listening comfort, sophisticated hearing protection and superior audio performance. The amplifier includes Clearline audio to enhance speech clarity in any environment, especially VoIP, which helps to reduce repeats, errors and listening fatigue. The Vista M22 is compatible with most office phones, and offers near-universal compatibility with single and multi-line telephones, as well as ergonomically designed volume, headset/handset and mute controls. A Quick Disconnect feature between the amplifier and the headset lets you move away from your phone without removing your headset or disconnecting the call. It comes with a 10 foot coil cord for freedom of movement while at your desk. Two year warranty. Features: Superior voice clarity with Clearline audio technology Delivers optimized audio levels for superior listening comfort Loud noise protection reduces the level of incoming noises, such as fax tones or whistle blasts to a more comfortable listening level Echo management for clearer calls Reduces background noise Volume, headset/handset and mute controls Adjustable incoming/outgoing volume One-button selection of headset or handset Supports tradtional PBX systems, standard VoIP and wideband VoIP networks Compatible with most office phones (not for use with cordless phones or phones with a dial pad in the handset Portable, battery-powered (2 AA batteries included) Options available: Standard ($119.95) Adapter ($145.95) For use with telephones that have a 2.5 mm jack