via this auction
"EXTREMELY RARE EMU VPDL PEDAL. This pedal was part of a larger EMU set up at one time. The [1/4"] cable length is 6' feet and is housed in a thick protective sheathing, so it is very durable and not prone to twisting. This pedal is extremely close in make and capability to the STEINER PARKER CONTROL VOLTAGE PEDALS from the 70's as well as the MOOG MODULAR CV PEDALS of the same time.
As you can see from the photograph, the pedal is marked "VPDL" and I believe this stands for VOLTAGE PEDAL.
IT WORKS WITH THE NEW MOOG GEAR AS WELL AS MANY OLDER ANALOG SYNTHESIZERS."
Sold For: US $54.00
via selectivepressure in the comments