Hi everybody !
This is simple tool, I managed to do without it in the past, but now I'm thinking I should have done it before (thought I had one made out of wood).
It is a ring mandrel, in order to turn both metal or wooden rings. It's basically used to finish the external profile, and apply the finish for wooden rings.
It's made of aluminum, The dimensions are 25mm largest diameter, 14 mm smaller diameter, taper is 16cm long.
Here I show it mounted on the metal lathe, but I can use it as well on the wood lathe.