Adds value to standard and wideband VoIP as well as PBX phone systems, protecting your investment through future telecommunications system upgrades. ClearlineÂTM audio technology improves call quality, enhances speech clarity, manages echo effect, reduces background noise and equalizes volume to maintain user"s listening preferences whatever the quality of incoming calls. Quick DisconnectÂTM feature lets user walk away from the phone without removing the headset or losing the call. Easy-to-use with one-button headset/handset selection, plus controls for both incoming and outgoing volume. For Use With: VoIP and PBX Phone Systems.