Definitely looks like a European design, and appears to be intended for use on a 240V system, not 120/240 as we use here in the states. Check the ratings on the main breaker.
Probably gold plated by one of the audiophool "tweaker" companies, to be sold to folks with more money than brains.
Before installing it, I would definitely run it past the AHJ to see what he says about installing it on a 120V system. He may not be too happy about the switched neutral, either.
Are you planning to feed this with oxygen-free liquid nitrogen-cooled superconducting romex? And call the PoCo for a platinum-wound pole transformer?
Seriously, if you do install it, make sure the customer understands you make no claim that this install will have any effect on anything but his wallet. Working for the "golden ear" crowd can be an exercise in frustration, as they moan and complain about problems that they claim to hear, and treat you like an idiot because you (and your best instruments) can't find anything wrong.
[This message has been edited by NJwirenut (edited 10-10-2006).]