1977-78 Electro-Harmonix Black Finger compressor(sustainer).
All original (from what I know, I’ve owned it since the early 80s). It does have wear and scratches as one would expect for a nearly 40-year-old stomp box, and 3 out of the 4 cover screws are missing. It functions as it should. It is 18 volts and is powered by two 9-volt batteries (not included). The pots were manufactured in 1977, so I assume this pedal was made/sold in 1977 or 1978.
Just an FYI (disclosure), this pedal does not function as modern compressor pedals do, it does NOT boost the signal or level even at full volume. It is NOT full bypass, it IS somewhat noisy, but it is a VERY COOL VINTAGE pedal!