This is a manually controlled bandpass filter module. In addition to the normal controls for frequency and resonance, there is a control for blending the filter's output back in with it's input to give a finer degree of control over the sound. This is combined with a phase reversal switch for the filter's output which allows for notch-like outputs when combined with the blend control.

The board features PC mounted pots for less wiring, and mounting holes for flexibility in panel layout. There are Eurorack and MOTM power connecters.

Here is a youtube video that shows that demonstrates the module's capabilities.

For complete information on this module and some mp3 demos, download this PDF file.  

PCBs are for sale for $8 each.
Unfinished panels are for sale for $8 each. Please read this page on unfinished panels before ordering.
If you'd like to drill your own panel, here is the drill guide that I use to make these panels. It should be printed at 300dpi.