The Omniflex is the RWO product. There are lots of choices but the best one will be the one that allows a big "flop" angle so that when you raise the rudders the base doesn't tear off the crossbar (or bend the extension or dent the crossbar). Yes, you could lay the extension off to the side before raising the rudders but the ONE time you forget, damage will occur.

Here is a link to lots of extension universal joints.

If you find the perfect universal and the best extension length please post it here.