I was hoping to tie this into the discussion of spinners, but I will just comment here. First, THANK YOU LARRY, second this shows how little difference there is between the F200 and the F200H. The hub is the same except for the hole drilled near the flange and the hydraulic cylinder that replaces the plate that goes on the front of the hub. Kent told me that an F200 could be changed to an F200H with only drilling the oil outlet hole in the flange and putting the hydraulic cylinder on the front, with a pipe joining the two. I think that there is a piece of linkage that connects the cylinder to the inner works of the prop, but no major changes. Interesting stuff about how to eliminate the plateau altitude that seems to be complained about with Aeromatics. That spinner support seems so much better than the other F200H props that I have seen. I wonder who made it? ____Grant. P.S. I have had 2 Hi-Cruise hubs and the cylinders were a little different on each of them. Just another mystery.