This is a Rat Shack Wall Volume control with a 4.7 uf non-polarized Cap across the in and out positive terminals. The cap is to preserve highs at low volume. Goes from 0 db (full volume - no attenuation) to -oo db (infinity - off) at 6 and 12 DB steps. I have the data-sheet somewhere that I'll try to find and post. I stuck it into a Rat Shack project box I had and put the chicken head knob on it with an IN and OUT jack (on each side of the knob - left is in, right it out). Thanks to ZaphodPhil for the idea and directions.