Sorry, I got the company name confused with the company that makes rotary heads. Here's the company that does Z33 diffs.

http://www.torvec.com/products_isotorque.html

...and in case you're the curious type, the company I got them mixed up with makes these very interesting spherical valvetrain systems. Someone with deep pocketbooks needs to check these out.

http://coatesinternational.com/