Tested this with an Oscope to 50 khz with square waves. Input and outputs were identical. The box is potted so you cannot see how it is made. It is a Bedini Interface enhancer of some sort. Basically an input connected directly to an output.
I have no idea how much it cost or how many they sold.
That being said, I hear better defintion, sound stage, lower noise floor and a tube like holographic midrange when inserted into my system, and would part with this vintage gem for just $1000
.