This antique crochet hook allows for the removal of the hooks to change sizes. It was probably once part of a set with multiple hooks, though it just has the one now. The handle is beautifully carved of ivory with an acorn like finial at the top. The tiny steel hook has a faceted collar at the top and it screws into the handle. It's about the same as an American steel size 11.
The condition is excellent with no chips, cracks or other damage and the ivory has a nice old patina and grain pattern. It screws together securely and measures 4" long.