The model SMH1783-11 (1-HW261 Headset, 1-M22 amplifier and 1-SSP1064-04 which is a monitor receiver for voice and dictation).
This headset provides a telephone headset on one ear and a listen only ear phone on the other ear. The listen only ear phone can be plugged into almost any sound source such as a computer sound card or a dictation machine. Custom made item so lead times vary. Custom item, not returnable or cancellable.