St 3000 spinner
I`ve had a cheap Chinese 3" dia. metal spinner on my ST3000 mounted in a Nosen Citabria for well over a year now.
This thing cost just a fraction of a Tru Turn or Dave Brown item - I know - I checked out both of them, and has performed flawlessly.
I wouldn`t hesitate to use a 3" Goldberg plastic one either.
Alan W