MXR Phase 90, block logo version with a potentiometer date code indicating 1980. It has some cosmetic wear, including the common notch in the enclosure for a 9V adapter, but really is in decent shape for its age. I had to replace the worn out battery snap when I got it, and I discovered the pedal still had the old notorious foam in it. So that all got cleaned out and the board got scrubbed thoroughly with iso. While you can see evidence of the foam’s evildoing, all of the traces test good with a multimeter and it works like it should, so it seems we got the foam out before it created any problems. Saved it!