Module is available as a DIY project only.
This Module is currently available.
Fixed Passive Filter
The FPF Fixed Passive Filter is a simple utility filter with fixed cutoff frequencies for Highpass, Lowpass and Bandpass. If you want to roll off the high frequencies or eliminate some rumble on synth sounds it does a pretty good job cleaning up signals. It is a simple passive RC filter combination and therefore causes a little loudness drop on your signal. This DIY kit is very beginner friendly.
It is currently available via Exploding Shed (EU shipping only).
These merchants probably sell this module. Huh?