Available in all 1U formats
Available as an assembled Module and as a DIY project.
This Module is currently available.
Triple channel Format Bridge
FB3 allows sharing signals between Eurorack and systems using 4mm banana connectors usually found in modular synthesizers in 4U format, like Buchla and Serge.
The ground is accessible on the back of the unit via a screw terminal and can be connected to the system ground, or used to transport ground from one FB3 to another.
Custom colors are available for the 4mm connectors.
http://www.xodes.net/product/fb3-triple-format-bridge-eurorack-banana-buchla-serge
These merchants probably sell this module. Huh?