You probably don't need an amplified handset with those phones. You can use the built-in amplifiers. While talking on the handset, increase the volume by repeatedly pressing the right side of the volume bar at the bottom of the face of the set. I haven't needed any additional amplification for anyone yet. One 2616 set in our office doesn't work as a speakerphone. I swapped phones, so that isn't it. The speaker works, but the person on the other end can't hear me when I test.