Potentiometer casing indicates a manufacture date in 1980. I know I've owned and used this for over 30 years, great for classic chicken pickin tones, smoothing out electric bass dynamics, etc.
Very good condition, works perfectly. Includes the pictured rubber knob grips and original foam rubber pad backing.
Has a custom mod where a 1/8th inch power jack was added to the top of the case.
To use external power, plug the two 9V clips together.
To run from a battery, separate the 9V clips and connect the battery to the black connector.