IC-2000. 12 inch cable interface between radio (TX REQ port)  and tuner. Does not supply DC to tuner. Works with Z-100(Plus), Z-11Pro(II), AT-100Pro(II), AT-200Pro and other generic LDG tuners.

Radios:
FT-2000

Functionality:
Pressing the tune button on the tuner changes the mode of the radio to CW, tunes, then returns the radio to the previous mode.