What is the application for these?

[speedo]

They are obviously spacers, but for what manifolds and engine?

Thanks

Speedo

[jittsl]

My 69 912 used something that looked a lot like those under its Solex carbs as isolators and vacuum connectors for the distributor.

[speedo]

Is the use primarily for 912 Solexes? Or could they be used as insulators for webers?
I am going to compare the ID measurement and stud size to a weber 3 barrel. I think I use PMO insulators on my race car, and maybe these would be an option?

Speedo