Passive Stereo Splitter
The Quantic Explitizer is a simple 2hp splitter for stereo signals into mono. It was built specifically for interface with the Keith McMillan Qu-Nexus but can be used for any sort of stereo interfacing. It is passive so can also be used to combine mono signals into stereo.
http://www.noiseengineering.us/quantic-explitizer.html
No info about availability.