Moomba Flow The new Wake Enhancement Device
Joe is right but there are 4 lag bolts on the bottom not just two
The blade is held in place by the big bottom pivot pin and the spring loaded pin. It is sandwiched between the mounting plate and the outer plate. There is a spacer plate on the interior side of the assembly to maintain the spacing created by the blade on the outer side which is held in place by the two bolts on the interior side.
Moomba Flow The new Wake Enhancement Device
I would agree about the cost the only challenging part about the machining is the mounting plate to boat contour match up but I am sure they obviously have the CAD model for the hull mold, so just cut a section from the model and make that your mating contour on your bracket and your all set with no real additional design work necessary with regards to that part.
What will be interesting is to see if folks start making there own blade designs to tweak the wake since the concept is simple to swap them out. The only concern I have about this would be exceeding the pull out force on the mounting plate.