Used WD Blue Clipper
It has been tested and works as it should. It's in great condition for being an older unit!
Unpleasant high-order harmonics are eliminated by a low-pass filter leaving only a full, rich, distorted sound. When the Clipper is switched on, the instrument's volume control adjusts the amount of distortion. The output level of the distorted signal is adjusted internally to balance the fuzz loudness with the normal output of any instrument.