Built-In Recorder Interface allows you to connect a recording device for recording all voice interactions
2 Headset Jacks Adjunct Jack used for connecting compatible adjunct equipment such as an S101A or S201A Speakerphone, a 507A Adapter, or a 500A Headset Adapter
Other buttons include: Drop/Test, Conference/Ring, Hold, Transfer, Release, Log in, Mute, Volume Control.